The music throughout the big fights. From "Heroes Successfully Cross Over the Daduhe River" for the Casino fight to the "Decree of the Sichuan General" for the Pig Sty Alley brawl to "Nothing Ventured, Nothing Gained" for the Axe Gang.
The fight between The Axe Gang and The Three Masters. The intro showed the Axe Gang to be an unstoppable force. When the gang appears at Pig Sty Alley after Sing's antics, they prepare to set a woman and a child on fire to flush out whoever harmed their member earlier. Coolie saves the pair by catching the lighter, then singlehandedly takes on the gang. When it appears that Coolie might be in over his head, Tailor, who had been shown to be a effeminate sissy, rips off his shirt, revealing his well-built form, and lends Coolie an assist. When the Axe Gang members go for their guns, Donut uses his kneading staffs to disarm them and destroy their weapons. As a result, Coolie, Tailor, and Donut deliver a Curb-Stomp Battle to the Axe Gang and send those that weren't knocked out running.
The Tailor does not put on his arm rings in any fashion resembling "normal"; it's either yank them down from some curtains or have them stacked on a table (where he then slaps the table hard, shooting them up into the air and down onto his arms).
The fight between Donut and Tailor and the two Musical Assassins. Though it's also tragic due to Donut, Tailor and Coolie's deaths, it's also one of the most awesome fight scenes in the movie and the only scene where you're missing out if you aren't watching it in surround sound (or at least a good pair of headphones.)
The Landlady and Landlord showing up and handing the assassins their asses at the end is awesome, too. Especially when the Lion's Roar leaves the assassins in only their underwear!
After beating the Musical Assassins, the Landlady and Landlord suddenly appear in Brother Sum's car and mutely warn him not to try that again (with the Landlady actually impersonating some of Bruce Lee's tics). Afterwards, Sum is so shaken up that he sets his greasy, slicked-back hair on fire trying to light a cigar.
The Lion's Roar definitely counts. Especially with a mega-phone in the form of a bronze bell. Even The Beast didn't know what hit him.
The Landlady using a funeral bell with the top ripped off as a makeshift megaphone for her Lion's Roar. The result is strong enough to shred the entire building they are in.
The Beast and the middle-aged Battle Couple are tangled up like a human pretzel. Gangster-Boss Brother Sum tells Sing to hit the couple with a railing post and help the Beast. Sing gets pissed and hits Brother Sum, who screams like a little girl. That's the Awesome. Then Sing, who all movie long has been pretty much a Minion with an F in Evil proceeds to hit THE BEAST with the railing post. That's the Heartwarming. The Beast comes close to a literal Curbstomp Battle with Sing, let's call it a Floor Stomp instead. Point is, Sing is beaten to near-death. With tragic music playing. That's your Tear Jerker. The Beast asks "Why did you hit me?" Sing's response? To fumble for a tiny little stick off the floor... and hit him in the head AGAIN. That's the Funny. The Beast then smashes Sing's face into pulp. Don't fret though, he gets better.
The final fight between Sing and The Beast. All around awesome, but especially the finisher, where Sing gets thrown high up into the air, through the clouds, and he then sees a cloud that looks like Buddha. He then starts falling down, his shirt actually starts burning up, and aims a descending palm strike at The Beast. He never even actually touches him, either- the sheer force radiating off of the attack is so great that The Beast is immediately blasted into the ground in a giant crater shaped like Buddha's Palm.
The Beast then attempts the same I Surrender, Suckers trick he earlier pulled on the Landlady and Landlord, begging for mercy only to get up and lunge at Sing to try and stab him with one of his weaponized flower ornaments (which is actually a minor moment for The Beast, just for being able to even take a hit like that and still get up). Sing's response? Almost nonchalantly throw out a second palm strike, deliberately missing The Beast's head by an inch and blasting a second, massive palm-shaped hole clear through the building behind him. The Beast immediately surrenders (for real this time), and, after Sing offers to teach him the Buddhist Palm, tearfully drops to his knees and acknowledges Sing as Master.
