Being an anime with a musical theme, RahXephon's music is all pretty good. However, the crowning song of the series has to be what's generally called "Ayato's kill theme." The actual song is called "The Chariot", and if this song starts playing, someone is going to die. Very. VERY. Painfully. Generally any time The Chariot starts up, Ayato has completely forgotten any kindness or compassion for anything at all, and is seriously just going to tear your mech in half with his bare hands now.
"Solitudes" perfectly captures the loneliness and melancholy of the series.
Much music from Ranma ½, which is fitting when the legendary Kenji Kawai composed quite a bit of it. The bad news is that relatively little of the good stuff is available on Youtube. The good news is that there's a highlight.
The very catchy opening 1. All the various opening themes can be pretty catchy, but season 1's "Yapapa" is arguably the most well-known. Bonus point: the version sung by Shampoo.
The fourth ending theme "Lambada Ranma" is also a very catchy song.
The opening 7 "Love Seeker" is explosive and frenetic with an energetic rhythm that is clearly inspired by Queen, especially their full version.
The rock song for the ending of the first Ranma 1/2 movie, It's Love.
Another Taku Iwasaki classic: The soundtrack to Read or Die. From the opening theme, which is a total homage to 60's spy film music, to the battle remix, to the British Library theme, it's all good. Special mention goes to "The I-Jin Suite"—creepy stalkerish percussion, butt-kicking electronica, and heartbreakingly sad piano and strings, all in one.
The soundtrack from Read or Die (both the OVA and the TV series) shouldn't be overlooked. There's the opening theme, the glorious, imperialistically bombastic Bring All the Wisdom to Great Britain, and last but not least, the edge-of-your-seat action theme Wings of the Gale.
The opening of the TV series is reminiscent of old-school spy and adventure serials in a completely awesome way.
There's also the second and seventh OPs, for the same reasons. Also, there's the fifth OP for a somewhat less upbeat example. Here's the "Varia Quality" version of the 7th OP; however, it is only sung by Squalo, Belphegor, and Lussuria.
"Tsuna Awakens". When it starts playing, you know Tsuna is about to kick some major ass.
"Hibari's Theme", which sounds as awesome as the the Disciplinary Committee leader himself.
"Flame of Resolution". When it starts playing, you know the Vongola will gain a wicked power or kick some ass.
The first opening, "Drawing days", is quite nostalgic and evocative of when the series was just a comedy series.
"Oretachi no Joy", sung by both Gokudera and Yamamoto, is awesome and quite adorable.
"Reborn's Theme" is also awesome and it's the first theme we hear in the very first episode of the series.
Red Line has an awesome soundtrack but the two songs that absolutely pop out are "Yellow Line" and "Red Line Day" - The first is a pumping rocking tune that is ideal for the action sequences. Red Line Day meanwhile is a gentle, breezy and somewhat melancholic track perfect for the movie's final scene and credits, wrapping up the anime perfectly. "Red Line Day" was also the inspiration for Undertale's main guitar riff theme.
While the anime has limited appeal, Rosario + Vampire happens to have some of the most awesome opening and ending songs that it makes you feel that they're wasted on mediocre anime.
Rozen Maiden: Zurückspulen (the 2013 series) gives us the awesome "Watashi no Bara wo Kaminasai" by ALI PROJECT as the opening while Annabel gives us "Alternative" as the ending.
Heck, try and find music from Rozen Maiden that does not qualify for this trope. (Hint: You can't.)
"The Last Wolf Suite", which could really be said to be the Kyoto Arc theme. It's suitably menacing and builds up the tension into awesomeness. That it's used for some of the best battles is icing on the cake.
Even if the synth brings the piece down a bit, Kizuna & Sadame is still the best single to come out of all the Saint Beast OP/ED tracks, and the way the seiyuus voices blend together is downright hypnotic.
The whole OST. To give an idea of its popularity in Japan, it was one of the first soundtracks to be released not with traditional J-Pop songs, but Background Music.
The opening "Pegasus Fantasy ver. Omega" is a nice callback to the original opening, which was also pretty awesome. The song starts off nice and sombre complete with a female singer (Shoko Nakagawa of "Ray of Light" fame, who also voices Saori in this series), then kicks off into a rock off similar to the original, even going as far as bringing the original singer for the song into the song.
There's also the second opening, Root Five's "Next Generation" (also called "New Ω Myth", though that doesn't seem to be an official title), which, as a rock/techno take on Seiya themes, manages to trade off a notch of bishonen for a notch of badass while still remaining surprisingly faithful to the concept.
Stardust Chant, the song that plays during episode 87 when Cataclysm Slash and the Athena Exclamation clash against each other.
"Obokuri-Eeumi", the song that plays while Mugen is drowning and flashing back to growing up with Kohza and Mukuro in Episode 14 is a Heartbreaking Moment. Doubly so when you understand the hopeful, wistful lyrics.
Every time "The Million Way of Drum" is used, it is a Moment of Awesome, ESPECIALLY the first time it is used in Episode 14 when Kohza realizes that her plan has totally and utterly failed because Mugen is still alive.
It even closes on a great piece. YEAH GOOD MORNING.
Death Wish, first played when Mukuro betrays and abandons Mugen on a burning ship and later gets a reprise in the Series Finale during Mugen's fight with Umanosuke.
"Hito Toshite Jiku ga Bureteiru", especiallythis version (although Kuusou Rumba does fit the tone of the series better). Actually, pretty much any SZS opening or ending theme belongs here.
The real Ultimate Awesome Song for Sayonara Zetsubou-sensei is not one of the openings, it's not one of the endings, it's not the rap versions of the openings, it's not that weird song about fishing or something, it's this, the song that shares the series' title, and deserves it.
The ending of School Days is an excellent example of how music can greatly enhance an entire scene. When Makoto recieves his "Goodbye" message on his cell phone, all sound and action stops for three seconds. Then "Kanashimi no Mukou e" sets in and almost drowns out the sound of the scene of his violent murder, and it keeps playing throughout the following scenes in which both his Love Interests try to kill each other.
The second opening, "Seven Deadly Sins", by Man With a Mission. This song gives a real sense of the true meaning of sin, making for one of the most chilled anime songs of early 2015.
Ending song #2, "Season" isn't half bad. Especially when you consider that the singer is a newbie.
Only used twice in the first season (specifically the first and last episodes) Perfect Time, a thrilling and energetic melody, gets you incredibly pumped when Meliodas is about to beat a fool down in epic fashion.
The Shiki anime has "Kuchizuke" as its first opening theme by a band called BUCK-TICK.
Also the second ED, "Kaze no Matsuri". Made even better when you learn that it's performed by Wuyuntana, a Mongolian singer.
Shelter is part short film and part music video for the song of the same name by Porter Robinson and Madeon. The song is a beautiful synth-pop tune that's equal parts nostalgic, hopeful, and heartwarming.
In Slayers, the epic instrumental music that plays for the Lord of Nightmares at the end of NEXT (and is later used for Dark Star in TRY and Zanaffar in Revolution). It can be heard here.
That little BGM that usually played when Lina powers up her high-end spells, namely, the infamous Dragon Slave.
"Live and Learn" being played over the finale of the Sonic X episode "Maria's Request Everyone's Request" is just as awesome in the anime as it is in the videogame. Unless you're watching the 4KidsMacekre. Then it's gone.
Considering it's done by the same guy who did the Gurren Lagann soundtrack (Taku Iwasaki), the Soul Eater original soundtrack rocks.
Both the opening "resonance" by T.M.Revolution and the first ending "I Wanna Be" by STANCE PUNKS are very energy-enducing and epic.
"STRENGTH." Basically anything abingdon boys school touches turns to gold. "PAPERMOON" is absolutely fantastic too. The lyrics sum up the series quite well.
"Counter Identity", the Repeat Show's first opening, not only lives up to the epicness of the original openings, but is also ridiculously badass as well. The second opening of the Repeat Show, "Ai ga Hoshii yo" made for a nice follow up.
Space Battleship Yamato's theme is so awesome that the Japanese Naval Self Defense Force band regularly plays it at concerts to this day! Wait till you hear the 2199version.
The whole soundtrack of Speed Grapher may apply but there are some serious highlights:
"Feast and Ceremony of Immorality" stands out for its eerie yet catchy qualities as well as being one of the rare tracks in anime to use horns instead of electric guitars or piano.
The opening, "Tabi no Tochuu", is just as awesome, because even though it sounds sad, the tune is good enough to make you want to play it on an instrument, or sing it yourself.
The opening theme for Season 2, "Mitsu no Yoake" is gorgeous, uplifting, and relaxing.
The soundtrack for the second season has several tracks that repeat the same melody with different instruments. "Matsuri wa Owari, Tabi wa Tsuzuki" is the most triumphant and weightiest of them.
"Hashiru" set the mood for a lot of intense chase scenes. Go figure, it means "run".
The dub theme from the obscure and oft overlooked anime Spider Riders, "Calling all Spider Riders!". It helps that it was performed by the talented Mr. Aubrey Drake Graham (better known as DRAKE).
"Mixed Nuts" by Official HIGE DANdism, the Season 1 opening, kicks in like a spy movie theme, and seamlessly switches to a rapid rhythm over lyrics about the series' main theme - different people, hiding their true selves from the others, slowly realizing that their false life is becoming real.
"Comedy" by Gen Hoshino, Season 1's ED, is a gentle song about someone trying to find a place to fit in only to realize that their place is the one they create for themselves.
"Souvenir" by BUMP OF CHICKEN, Season 2's opening, has a dynamic melody with lyrics of how, no matter what, you can always return home with your loved ones.
Starship Operators tops off an already superb soundtrack when the full, 5-minute version of the ending theme is played over the end of the last episode, and fits perfectly.
The series gives us the beautiful second opening theme "Yakusoku", by Suga Shikao.
Other awesome themes include the first opening of the season one, "Hajimari no Hi" by Suga Shikao and the first opening of the second season, "Chiisana Mahou" by Stereopony.
Tekkonkinkreet is an incredibly strange, yet sombre film. Naturally, the score captures that sombre strangeness with a mix of influences including Asian instruments mixed with electronica.
The song used at the end of the final episode, "Bless (feat. Arnór Dan)" is another memorable song from the soundtrack, especially when heard in context.
It might be becoming almost as repetitive as the stop-watch theme 'Melodie' is in Anime/{{Noir}}, but in Tiger & Bunny, "Barnaby", the theme associated with the murder of Barnaby's parents, is a very nice, very eerie piece. And then there's all of the OPs and EDs which are gloriously pop-y.
The first series' opening song, "unravel" by TK from Ling Tosite Sigure. Powerful alto vocals coupled with angsty guitar riffs only accentuate the lyrics that reflect Kaneki's inner conflict throughout the story.
Tokyo Ghoul√A's opening "Munou" by österreich, with its sorrowful and hopeless lyrics.
"Orange" from Toradora! can become Heartwarming just from the sheer atmosphere of the song. Even more if you juxtapose the show's grand finale with it.
"Orange ~Citrus Remix~" gets special mention for taking that song and giving it a slightly more rock-y and much more awesome feel.
The "Holy Night" insert song from Episode 19. Not only a really happy cute song but also a very Heartwarming Moment in the show.
Also, "Lost My Pieces" is one of the purest musical definitions of bittersweet.
"Startup!" is both heartbreakingly beautiful and incredibly inspiring.
"Pre-Parade" is one of the most nefariously awesome ear worms of all time.
The same thing can be said for the second opening, "silky heart".
"Getsumei Fuuei", closing credits song from The Twelve Kingdoms (Juuni Kokki), though it gets part of its affect from the lyrics and the context of the show.
The anime keeps up this standard, with another opening by Akiko Shikata, singer of the above, which uses most of the same elements to similar, yet somehow even more awesome effect. And then there's the anime ending, a dramatic male vocal on the JAM Project level backed by a dramatic chorus that sounds like an unused duel song from Utena. Even better than it sounds.
Anyone who has played the original visual novel (see Video Games) knows that pretty much the entire soundtrack is nothing but Awesome Music. To bring up one that isn't covered here or there, Beato's Image Song, "Chain" is just sublime.
"Mother land" by Yuuka Nanri. It was first heard at the end of Episode 8, but it truly gained this status in Episode 21, really adding to the emotion of Kyuma's Heroic Sacrifice.
Then there's the two closing tracks provided by Kanon Wakeshima, particularly the first, "still doll". Her girlish voice makes them almost delightfully evil.
The same thing can be said about the second ending, "Suna no Oshiro".
Vinland Saga has its first opening, MUKANJYO, an awesome rock track that captures the series's brutal tone.
The obscure and underrated anime adaptation of the Virtua Fighter games has some great opening and ending themes:
"Ai Gatari Nai Ze (Love is Not Enough)", Second Opening theme. Takanobu Mitsuyoshi, one of Sega's best composers, sings this and has claimed this song to be one of his favorites.
And as a special mention, there is this music video specifically animated for Jacky's song "Believe in Love" from the second game's image album Dancing Shadows.
"Mystic Eyes" may be about the only song in The Vision of Escaflowne that Yoko Kanno didn't have a part in, but that doesn't mean it still isn't cool.
There's two reasons Filipinos love Voltes V. The opening with its strong vocals and martial feel, and the closing which is melancholic yet oozes machismo.
Wagnaria!! has the unbelievably catchy first season opening "Someone Else" and the cutesy second season opening "Coolish Walk" to offer to this ever growing list.
The ending theme song, "Vidro Moyou", is simply divine.
The ending of the OVA gives us the beautiful "point at infinity". To make this song even better, they added echoes of "Vidro Moyou" in the arrangement of the song.
Wandering Son's ending theme, "For You" by Rie fu, is a mostly quiet song with Surprisingly Good English (not so surprising when you consider the singer was raised in Maryland and went to college in the UK). It's rather heart-warming, is quite relaxing and fits the Slice of Life feel of the series.
Wedding Peach has the second opening, Wedding Wars. The full version was played in the final episode.
Witchblade: pick any. Especially the main battle theme (Witchblade OST). "XTC" is at its best with video part of the opening, but is good even on its own.
The closing theme to Wolf's Rain is "Gravity" by Yoko Kanno and Troy, sung by Maaya Sakamoto. It's a touching and poignant song in its own right, but combined with the tragic events of the final OVA episodes it becomes totally heartrending.
X1999 (the anime version) has some wonderful music. Try listening to "Sadame/Destiny" without getting a lump in your throat. Managed it? Take a look at the manga/anime series/movie, then listen again.
The earlier anime movie, while sucky, still managed some awesome in the arguably emo X-Japan song "Forever Love".
"Ex Dream", the OP fo the TV series, is no slouch either.
From ×××HOLiC, we have the catchy while still somewhat creepy "19sai", a song whose sound fits perfectly with the show it starts off.
Regardless of which version of Yozakura Quartet you've seen, the one thing everybody can agree upon is that this series has some fantastic music. To wit:
On the surface, Zoids: Chaotic Century doesn't look like the kind of anime that would have a good soundtrack, but it does. In fact, it's got a great soundtrack. Just listen to the main theme, this, this, and this. You can thank Robert Etoll for such awesome music.
, and if this song starts playing, someone is going to die. Very. VERY. Painfully. Generally any time The Chariot starts up, Ayato has completely forgotten any kindness or compassion for anything at all, and is seriously just going to tear your mech in half with his bare hands now.