What I'm not looking is a manga in which the protagonist pretends to be stupid. The character has to be an idiot, although sometimes it may seem otherwise.
Some examples:
1/2 Prince - Prince
Tokyo Crazy Paradise - Tsukasa (usually she does behave like an idiot
![smile](emoticons/beigesmile.gif)
Gokuraku Seishun Hockey Club - I guess there's no need to explain this one
![smile](emoticons/beigesmile.gif)
Oresama Teacher - Hayasaka-kun (Mafuyu also has some idiotic moments
![smile](emoticons/beigesmile.gif)
What I find annoying:
- Weak, pathetic, clumsy idiots (Keitaro from Love Hina)
- People who get into trouble because their own stupidity and have to be saved by other people (Miaka from Fushigi Yuugi, I suppose)
- Extremely cheerful and optimistic characters (Tohru from Fruits Basket)
I don't like ecchi and yuri/shoujo-ai, but shounen-ai is fine.