The ones that are totally different from what they sound like they would be about from the titles.
One Piece: Sounds like an ecchi/hentai.
JoJo's Bizarre Adventure: Reminds me of JoJo's Circus. Sounds kiddy.
Bleach: Seems like a manga about the daily life of a mother that has to wash dirty clothes everyday.
The Melancholy of Haruhi Suzumiya: Sounds like an emo drama anime.