Anybody big fan of Yu Yu Hakusho? Got into that anime about a year ago, man it was awesome with the pissed off kid as the main character. Hiei is great, and Kurama is awesome too.
The best part though is the character development, they not only get stronger, but as the story moves on they grow as people & demons. Yusuke finally grows up at the end. Hiei isn't pissed at everything anymore, Kurama is finally at peace with himself & Kuwabara finally got his shit together too