For guys, I either like the cute boyish and playful types (Goku from Saiyuki, Kei from Beauty Pop) or the tough guys who know how to kick butt. (Mello from Death Note, Shinji from Persona 3, etc.)
In girls, I don't really like shy girls. I like the loud ones, people i can relate to. (Risa from Love*Com is my favorite manga/anime person of all time.)