Okay lesse... the main ones I'm currently reading on a regular basis/semi-regular basis.
Naruto, One Piece, Bleach, Majin Tantei Nougami Neuro, Muhyo to Roji, Mieru Hito, Nazo no Murasame-kun, D.Gray-man, Beet the Vandel Buster, Jojo's Bizarre Adventure, Konjiki no Gash Bell, MAR, Yakitate Japan, Ai Kora, Karakuri Circus, Hayate The Combat Butler, Dragon Quest: Emblem of Roto, Dragon Quest 7, Air Gear, Negima, Pokemon Special (well sort of. Don't have much access to it), Suikoden III, Milk Closet and Keroro Gunsou.
Would count Hunter x Hunter, The Law of Ueki and Gyakuten Saiban, but the first two are kinda on an endless hiatus and the latter only has one chapter.