Anything Nippon Ichi has done:
Disgaea 1-3
Phantom Brave
Makai Kingdom

Disgaea 3 has at least gotten some fame by becoming a PS3 title, but in general most people don't know about Nippon Ichi. Every game they've put out has an awesome art style and usually has a great anime-comedy story. Any game that has a weapon called "Beat Down" with an item description of "Make me my dinner, Woman" is a huge WIN in my book.