Wow, this is going to be hard. Well not really, lol. I am going to name a few I read. Some of them I haven't finished yet, but they are really good so far. ^^
Lovely Complex
Kare Kano
Kodocha
Chobits
Absolute Boyfriend
Power!!
Kare First Love
Tsubasa RESERVoir CHRoNiCLE
Marmalade Boy
It's Not Like That, Darling
Bleach
Naruto
Ranma 1/2
Sailor Moon Stars
I love these because they have a wonderful storyline. They have action, adventure, romance, comedy, fantasy, etc. And the art in all of them are amazing. <3 There are some more I love, but I just name a few. ^^