Jump:
Bakuman
Hunter x Hunter
Bleach
Naruto
The first two are waaay better. Too bad HxH is going on hiatus again.
Mahou Sensei Negima
Codebreaker (I don't know why I still read this)
Fullmetal Alchemist
Kuroshitsuji (it got licensed???)
Soul Eater
Witch Hunter - supernatural Korean battle manga
The Breaker - superpowered Korean martial arts manga
Player Kill - unpowered Korean martial arts manga
The Lucifer and Biscuit Hammer - superpowered (but not really that powerful) seinen battle manga. People die when they are killed :/. Also, the author's a big fan of FLCL and The Pillows, it seems. The two main characters lead a group to save the world from getting smashed by a biscuit hammer in the sky, but secretly the two are only doing so so that they can destroy it themselves.
Change 123 - ecchi female martial arts manga
Orange Yane No Chiisana Ie - Uhhh... a man and a woman get scammed into living together? Extremely slice-of-life. But I don't find it annoying, so I keep reading it.
Shiki - Vampire horror story. Except that you don't know that they're vampires for a long time. I mean, it's chapter 18 and one of the main characters JUST named the creatures "Shiki".
Seto no Hanayome - This YT vid is what got me hooked:
http://www.youtube.com/watch?v=qpi47qMAPt8My friend got hooked when he saw The Terminator dressed in a girl's sailor uniform in an epic battle of lots and lots of missiles.
I don't know what to say about these:
Baby, Please Kill Me - 4koma about a pair of schoolgirls, one of whom is an assassin.
Gonna catch up one day on Hayate the Combat Butler, Skip Beat, One Piece, Detective Conan (yeah right), Hajime no Ippo (yeah right), and Saiyuki.