I almost exclusively watch more dark/supernatural type anime.
- Hellsing Ultimate
- Black Cat
- Black Butler
- Blue Exorcist
- Tokyo Ghoul*
- Death Note
- DRAMAtical Murder*
- Vampire Hunter D and Vampire Hunter D: Bloodlust (they're movies but they're good movies)
- Black Blood Brothers
- Fullmetal Alchemist: Brotherhood*
- Pokemon* (the original series)
* Haven't finished it, but what I saw was good
Ouran High School Host Club is also amazing.