The lack of Aria here is disturbing -
Aria
20th Century Boys
Cat Street
CCS (mainly for tomoyo fanboyism, but w/e)
Hoshi no Samidare
Watashitachi no Shiawase na Jikan
Special A
Akumetsu
Besides that I could say Gokusen, Angel Densetsu, Deep Love series, Hikaru no Go, Rurouni Kenshin and many more, it's just that I don't like them enough to be my "favs", but still they deserve being mentioned