I assume you've been watching Bleach and Naruto now that they're out of those horrible fillers...

best show on right now: Code Geass: Lelouch of the Rebellion

Death Note is also pretty damn good if you enjoy mystery, cat/mouse dramas. Not alot of action but a good amount of WTF-craziness to be had. And, if you like Death Note at all, I highly recommend Monster, the best mystery/crime anime I've ever seen.

I also suppose you've seen Black Lagoon (both seasons) and the Melancholy of Haruhi Suzumiya, both excellent shows from 2006. Black Lagoon is straight up gangster awesomeness, Haruhi is a comedy, but it's zany and full of insanity that will certainly make you put some extra BBQ on your WTFs.

also a sci-fi/mecha mind-bender from last season: Zegapain

I'd also recommend Eureka SeveN: Psalm of Planets, but while that's a great show, It's not a show that you watch for shock effect, more for enjoying carefully crafted cinematography and awesome characters.

some classics, if you've never seen them, include: Hellsing, Gungrave, Berserk and Fist of the North Star.