Detective Conan. Really dark and logical. It's also makes suspense.
FFS, was hoping to be the first one to mention Conan.. Oh well just finished watching the marijuana bloodfest&yuki onna episodes huhhuh...
Darker than Black
Kindaichi case files (this is like Detective Conan and it's pretty gruesome, oldschool)
Psychic Detective Yakumo
School Days (This has real shock at the ending of the anime but otherwise it's not worth watching)
Soul Eater (The animes ending was so rushed, they started new anime called Soul Eater Repeat Show that hopefully follows the manga and the manga has not even been finished yet)
Another (was hoping it to be better)
Cant really say that I thought anything about FMA and Code Geass but I guess they were ok...
Death Note is most over hyped pile of crap i've ever seen so it's not getting on the list..really