Brooke was reviled during her run on the show and at the time of her death via drowning in the complex pool back in season four, few felt bad for her, but given how much more receptive modern audiences are to her character, you can't help but feel bad for her ultimate fate.
Craig has it even worse. Never popular with the fans, then or now, seeing him lose his newlywed wife, his business, and his fortune is pretty sad with all of this culminating in his Despair Event Horizon and suicide in season six, only to be almost immediately forgotten by everyone afterwards.
Angst? What Angst?: So you have experienced this massive explosion, your friends and colleagues are injured, some seriously, a woman died, you know that it wasn't an accident and all of your personal belongings are destroyed. A devastating and difficult to move on from event, right? Hardly; everyone just picked up, began rooming with one another and went on with their lives within an episode or two, well except for Peter, Kimberly and Alison.
Ass Pull: Michael and Taylor having a baby was so out of left field, especially since they barely had any screentime together.
Awesome Music: Whatever else you can say about the show, there is no denying the theme song composed by Tim Truman is an absolute banger.
Base-Breaking Character: Brooke. Some fans loved her due to her manipulative and bitchy ways and Kristin Davis' strong and believable performance as her. Others despised her due to being unnecessarily cruel to the show's Chew Toy Alison and for always bringing doom whenever she went. At the time, she was so unpopular with fans that the producers had to kill her off just to appease them due to the level of hatred her character received while in hindsight plenty of viewers wished it hadn't come to this, especially with the remaining storylines left from that season were largely hated. particularly... Kimberly's split-personalities, the Amanda-Peter-Bobby triangle and Richard becoming evil and raping Jane out of nowhere
Michael, Sydney, Amanda and Kimberly were exponentially popular amongst fans.
Lauren Ethridge, Sydney's pimp from season two. She was every bit the Manipulative Bitch that a pimp would be, but fans nonetheless loved seeing her and her interactions with her girls. Kristian Alfonso's portrayal of her helped a great deal.
Hayley Armstrong, Brooke's slimy millionaire father. He was only in 14 episodes, but fans enjoyed both his presence and Perry King's acting.
Fanon Discontinuity: A good number of fans of the original series don't acknowledge anything that happened in the reboot.
Fridge Logic: How exactly did Jake manage to escape the boat filled with bombs and dynamite before it exploded? The button was pushed just as he had discovered them.
The episode where Kimberly blew up the complex that was originally to air in the season 3 finale (which was pushed back due to the then-recent Oklahoma City bombing) ended up airing on September 11, 1995.
Alycia Barnett, Peter's one-time girlfriend, died while talking on a car phone as she was behind the wheel. Odd at the time, more relevant nowadays given how many people who have been injured or killed due to talking/texting on their phones while driving.
One season three episode had a drunk-driving Alison run down a young man who, although injured, ended up surviving. Several years later, the same incident happened to Amy Locane, who played Sandy on the show, only one of the other people in the other car didn't survive and she went to prison for a few years as a result.
The saga of Brooke losing her father (and his fortune), having problems in her marriage that ultimately ended it, losing her job/going into debt and eventually dying herself is reminiscent to the Real Life issues that Melrose Place executive producer Aaron Spelling's daughter Tori would face many years later (although fortunately her marriage didn't end nor did she die).
He Really Can Act: Who would have guessed that Prettyboy supermodel Antonio Sabato, Jr. could pull off the role as the conniving, Manipulative Bastard Jack Parezi from season four so well?
Kimberly's prim and proper split personality of "Betsy" from season four may have been a predecessor to actress Marcia Cross' eventual Bree Van de Kamp character from Desperate Housewives.
You would think that Brooke, who the writers had brought in as a rival to Alison for Billy's affections and was basically set up to give us a character to root against, would have already had this after her treatment of Alison, namely the disaster of her being fooled into producing one particularly insensitive ad campaign that unintentionally made fun of the suicide of a client's mother. However, what really caused her to go into this was her going through Amanda's personal files and not only finding out about her abusive ex-husband and that she faked her death to get away from him, but also contacting him to invite him to L.A. so he can find her again, just so she could blackmail her into promoting her over Alison and which pushed the reset button on Amanda's Heel–Face Turn. After that, any fans she may have had turned on her.
Speaking of Jack, while his past and present abuse of Amanda is cruel enough, but he didn't truly hit it until after he went to L.A. to seek her out. When he fell in his home while trying to kill her, this landed him into a coma with brain injuries and once he them came out of said coma, he lured her into thinking that he would leave her alone to live her life, only for him to try to strangle her and die of his injuries before he can do it.
The Henry storyline. It was supposed to be seen as a sign of Kimberly's Sanity Slippage, but the ridiculous acting of Henry and her reactions to him usually invoked laughter instead of fear. Plus his words alone and indeterminate accent added onto this factor.
Brooke in her final episode, whom we are supposed to feel sorry for, but due to her actions over the season and the hilarious "scrunchy face" she gave that was supposed to show that she's upset and about to cry, it came off as this.
As powerful(and heartbreaking) as Sydney's death was, Craig's reaction comes off as this. Interestingly enough, the actor doing the Spanish dub of that scene provided more raw and genuine emotion in his portrayal over the original English acting scene.
As rough as Alison had over the series, one of her earliest hardships was an entire episode dedicated to the untimely death of the beloved "Betsy"...her car.
Questionable Casting: Plenty of instances throughout the series that made fans wonder why were they cast, but perhaps most notable is then-MTV host Dan Cortese as Jake's wayward, estranged older brother Jess Hansen. Even as being just half-siblings, the two looked nothing alike, he was cast as the "older" sibling in spite of being obviously younger and Cortese's stilted acting makes one wonder what one was thinking in hiring him.
Overall, Peter and Amanda being with anyone else is regarded as this, but specifically her relationship with Bobby Parezi in season four. Aside from how hated the storyline was (partially due to the latter character who, even as a Nice GuyHitman with a Heart, was the less interesting of the Parezi brothers) and that it took away from the better storylines of the season, like the Billy/Alison/Brooke triangle and Michael vs. Kimberly.
Taylor is very hated due to her scheming ways, her rather sick reason for pursuing Peter and having too much airtime in what is widely regarded as the worst season of the show.
Samantha is considered this among the fandom as well, due to both her and her worthless, ex-con deadbeat father (the best example of the MALE scrappy of MP) running down Sydney at her wedding AND that fans considered her too bland and a far more boring wife for Billy.
Seasonal Rot: While seasons six and seven are often blamed for the show's downfall, where most of the show's original cast were replaced by an array of Suspiciously Similar Substitutes (Jennifer for Sydney, Kyle for Jake, etc.), season five is where it truly began, where many of the popular characters either left or were killed off, characters' backstories were retconned, and the storylines became even more contrived (if not rehashed) than usual.
Strangled by the Red String: Plenty of occasions, but Jake and Alison was the best example. The two of them were friends for the past four years when, out of nowhere, they fell in love, Alison became pregnant, they were married and Alison was forced to terminate the pregnancy due to medical reasons. Come the end of the season, they were split up, Alison left L.A. and Jake decided to go live with his ex-girlfriend and their son in Ojai.
Dr. Brett "Coop" Cooper. Having been introduced with a potential revenge storyline against Michael as retribution for ex-lover Kimberly's death, the show dropped it after several episodes. Ultimately spending half a season being begrudging business partners with Michael and Peter, Brett didn't have much to do, except fight with Peter, Michael, and ex-wife Lexi.
Too Bleak, Stopped Caring: With frequent and near-universal backstabbing, moral ambiguity, and bed hopping, Melrose Place could elicit this trope in the eyes of the audience and longtime fans, who have seen these storylines over and over again.
Kimberly is supposed to be one of the main antagonists of the show. While some of her acts can't be forgiven, especially the fact that she willingly started a relationship with a married Michael, her past, the mistreatment she suffered at the hands of Michael and other people on the show, her moments of clarity, remorse and genuine concern (especially in season five) and her ultimate Downer Ending made her a lot more sympathetic to fans than the writers probably intended.
Sydney creates utter havoc wherever she goes, especially for her sister, but it's also clear that she's never been properly loved by anyone, her parents see her as the Black Sheep especially next to her older sister who is the clear favourite, she's treated terribly by Michael whom she genuinely loves, she's later raped by her sister's boyfriend and no one believes her, not to mention the many times she's kicked when she's down, including being beaten up by a group of prostitutes, forced to work as a stripper to pay off a debt which was incurred because her business partner screwed her over, framed for the hit-and-run of Michael by Kimberly, and the various times she tries reaching out to Jane only for Jane to slam the door in her face. It's hard not to feel sorry for the girl.
Alison goes through a lot of trauma over the seasons, including being stalked and attacked by an ex-boyfriend, childhood molestation at the hands of her father and being forced to terminate a pregnancy due to health reasons, but she is also incredibly self-centered, turns into a monster when she is promoted at work, cheats on various partners, seems to only ever want her love interests when they're not available and often comes across as a Bitch in Sheep's Clothing, due to her inability to ever take responsibility for her own actions.
Wangst: Dear Lord, Craig in season 6. On one hand, it was understandable (becoming a sudden widower, especially in such a violent way, does do that to a person), but on the other hand, the writers took it up to eleven and let him wallow in misery throughout the season, culminating in him being Driven to Suicide in the season's penultimate episode.
Jane's supershort, lopsided "pixie" cut throughout much of season four was universally hated/mocked by the fandom, with many believing she had it cut by a lawnmower.
Perhaps an even worse overall look went to Sydney from that same season, whose hair and wardrobe was trapped in the 1960s.
Why Would Anyone Take Him Back?: All over the freakin' place. Kimberly and Michael, Jane and Michael, Amanda and Peter, Billy and Alison...
Pretty much every female character (as well as Matt) in varying degrees, but specifically Alison, Jo and Sydney, who occasionally was also a Jerkass Woobie.
Kimberly was also a Jerkass Woobie. Some of her behavior was truly wretched, but given her past and what Michael put her through, she often came off as sympathetic.