Emily Valentine and the Homecoming Float
Emily didn’t show up until second season, but as soon as she got on the scene, Brandon was all googly for her. Which of course made Ahhhhhhndrea super jealous, which of course added to the appeal. 
Emily was all wild and stuff and she wanted to show Brandon what actual fun was, so she took him to an underground rave and gave him drugs without telling him (because that’s what cool girlfriends do) and they couldn’t call it ecstasy for unclear reasons so they were all tripped out on euphoria, which actually sounds quite pleasant. 
Brandon, despite his drunk driving and burgeoning gambling habit, goes all psycho at Emily and won’t see her anymore and Emily for again, unclear reasons, is so hung up on Brandon that she slashes her own tires to get him to come over and stalks him and blah, like his shelf hair is worth pining after. Brandon is in moralistic mode instead of self-destruct mode (he only has 2 modes) so is impervious to her efforts to win her back and she FREAKS OUT and is all I’m going to be alone forever and I can’t hang out with the gang anymore oh no and pours gasoline all over the homecoming float they built. That’s the end of her for this round, but she shows up several seasons later and Brandon pines for her off and on and her hair gets a lot better later on.
