Not that I hated the character at all; I think he's one of the best devised characters in this generation of gaming, but the Joker in Arkham Asylum. I choose him only because he's THE classic villain and his death came out of nowhere. You never expect a Marvel or DC comic book character to die because they're worth too much, so when they do, it comes as a massive surprise.
Obviously given the aftercredits, it's not confirmed that he's even dead, but John Carver in Dead Space 3 was a character that I never really liked right up until the end of the game. I only played the single player, so maybe you get to know the guy better in co-op, but he mostly just shouted at Isaac for most of the game. But then when you enter the machine and they're both exploring different areas, their dialogue actually really made him feel like a character rather then just an empty shell for a second player to jump into if they felt the need. Then when the moon blows up and the only person you hear speaking at the end is Isaac, it's disheartening.