>>10 Agreed on Blazblue and Crisis Core.
If you're any good with rythm or just want a game thats fun, dunny, colorful, and yet has a very simple story and controls, then I recommend PATAPON, PATAPON 2, and PATAPON 3. The third might be a bit more confusing.
There's also Prinny: Can I Really Be The Hero? and Prinny 2: Operation Panties for a good old Disgaea laugh fest.