I've got a bit of a list, but this isn't everyone ^^;:
Sasuke Uchiha (Naruto) - C'mon, we all hate him. He never shuts his mouth about revenge and all that crap, and he's just an annoying d**k.
Sakura Haruno (Naruto) - Really...must I?
Naruto Uzumaki (Naruto...duh) - I don't have to explain him either.
Actually...practically EVERYONE from Naruto.
Everyone from Lucky Star - Dear god, they're all annoying as hell.
Creed Diskenth (Black Cat) - He's too overly gayly obsessive over Train. I don't hate him, I actually like him. ^^ But yeah...he obsesses over Train too much, which is annoying. Oh, and for killing Saya too. ;>3>
Luchia Nanami (Mermaid Melody) - She's the most terrible main character of something I've ever seen. Must she cry over EVERYTHING? ;- o-
Winry Rockbell (FMA) - She's annoying, gets in the way, never shuts the hell up. And I don't think she'd look so nice being paired up with Ed. D:
Orihime Inoue (Bleach) - Useless...that's enough.
Risa Harada (DNAngel) - She fan girls over Dark like a freak, she's selfish and stubborn and acts like an idiot all the friggin' time. Riku's much better. =3=
Higa Izumi (Sekirei) - I want to tear him to shreds. He speaks the truth, but says it so harshly. D:<