A huge cross-genre hit that opens with a giant beat and builds to a memorably weird hook sung by a guy who's not a singer. Sound familiar? Are you shaking that Polaroid? Like Hey Ya, Crazy is a song about sadness ("My heroes had the heart to live the life I want to live/ And all I remember is thinking I want to be like them") that made a lot of people happy. Danger Mouse's space-age funk production has something to do with it, but mostly it's Cee-Lo's sometimes on-key, sometimes screeched vocal, so warm and deeply felt that he makes collective insanity seem like a small cost for the privilege of just connecting.