Gitaroo Man.
http://www.youtube.com/watch?v=NHLGg-GS5Fc
Awesome, weird, uniqe characters and story.
I love it.
And the soundtrack is one of the best I've ever heard.
I still listen to it almost every third day. ^^
Singstar, GuitarHero & Co. are fun at partys, but karaoke doesn't count as a game for me.
Original songs? No.
Story? No.
Anything unique? No.
So, no "real" games, imho.
But great fun when you're drunk. ;-)
-EDIT-
I totally forgot to mention REZ and Audiosurf. Also great games.