Shinn Asuka from Gundam SEED Destiny. I've noticed alot of people don't really like him, complaining he's emo. but what can you expect when you're 14 years old, and your whole family dies, right before your eyes practically?

EDIT: whoops, didn't realize this was old.

there are people who DON"T like Kyoya?! I love him. Are talking about the manga or anime? because kyoya in the manga is better, in my opinion. Orochi is awesome too. I just made a really creepy youtube video of him.

Zuko, from Avatar.

Hoshino Aya from Super Gals! and Ryuuzaki Sakuno from The Prince of Tennis. I understand why people prefer Ran than Aya: after all, Aya's a crybaby and an insecure fellow (hey, we have insecurities too!) who can't decide on her own; she'd rather follow [what] others [want], which really annoys Rei. But as the story progress farther, her personality changes a little and she's less cowardly. I appreciate how the manga artist had portrayed her even if she seemed so weak and irritating from the beginning until the end.

Now how am I actually supposed to know which Anime character is generally hated by fans? I do have a habit of liking cameos or unimportant characters in mangas & animes, though.
Anyways these includes: the Triplets from Kuroshitsuji season 2 anime, and Snake from the Noah Ark's Circus story arc. Will of Abyss and Glen Baskerville from Pandora Hearts, Sera Masumi and Subaru Okiya from Detective Conan.

I am OBSESSED with Envy from Full Metal Alchemist. Everyone hates him because he killed Hughes. I loved Hughes too guys but you have to get over it. Envy is just incredibly appealing to me. In every sense of the word. Please stop hating him! TT^TT