In no particular order:
1. Naruto (ninjas!)
2. 20th Century Boys (best manga I've read story-wise)
3. Blame! (best manga I've read artistically-wise)
4. GANTZ (this is so twisted, I luv it)
5. One Piece (pirates are fun!)
6. Yakitate!! Japan (such a funny manga about baking bread, makes me hungry)
7. Count Cain (wicked version of Sherlock Holmes, dark shoujo)
8. Bleach (kickass story and action and Rukia rocks)
9. Berserk (medival gore goodness with a hint of romance)
10. Zombie Hunter (plenty of gore, cool story, awesome art, luv it)
Those are my current top picks, but the list changes as I read more titles. Either way I found these titles, as well as the aformentioned ones, to be good and interesting reads. Enjoy!