Lixaxy, I prefer shorter manga, like one shots or series that have about 20 chapters, but if it's a really good manga and has over 20 chapters, I wouldn't mind reading it. I'm not a fan of teacher-student relationships neither student-adult, I'm more for students couple. For genres Romance should definitely be there and Comedy, maybe Drama, but Tragedy is kind of too much. Yeah and I don't like Harem. I like more recent manga, let's say from 2012, which have better drawing quality, like Hirunaka no Ryuusei.
I'm currently reading Omoi Omoware Furi Furare, Nijiiro Days, Tsubaki-chou no Lonely Planet, Harumatsu Bokura and other ones, but because they don't translate to English much often, I need to wait.
From the list you gave me I have read most of them, but the Hatsukoi Hajimemashita seems interesting, I'll give it a try.
Thank you for your reply and sorry for the demands I have.
btw Last Game is really good, you should definitely read that, it's really sweet :)