Black Lagoon was the last half decent anime I saw, and that was like what, half a year ago. It's hard for me to get into anime anymore to be honest, I'm losing interest with each passing day, I feel like I saw everything worth seeing. I need something good, something to bring me back. I'll list some of my favorites so you can get general idea of what I like...

- top tier

Cowboy Bebop
Death Note
Dragonball Z
FullMetal Alchemist/Brotherhood
Fruits Basket
Golden Boy
GunGrave

- mid tier

Black Lagoon
Code Geass
Full Metal Panic!
Rurouni Kenshin
Samurai Champloo
Vision of Escaflone
Z.O.E. Dolores,i

... there you have it, let's hear your recommendations, and please go into details as to why I should see that particular anime. Also, medium sized anime if possible, avoid the likes of Naruto, Bleach and One Piece, filler fests with no end at sight.