I don't like Twilight because:
The characters are terrible, with no personalities, and are Mary/Gary-sues.
The writing itself is not good, except for when describing people, but, hey, shallow characters, shallow writing.
Edward is a dick and stalker, Bella is an airhead who should die - but God forbid could <.<
The "romance" and "vampires" are pitiful and stupid and unrealistic (<--I'm pretty much only talking about the "romance" with the unrealisticness, not "vampires") and the author is a hypocrite to her own mythology on "vampires".
I think that's it <.<