I never realized what little 'happy' music I have until you asked. I have music that gets me "pumped up" (for lack of a better term) so I guess I'd go with alternative rock - bands like Queens of the Stone Age, Filter, Smashing Pumpkins, Toadies, Pixies, Primus, RHCP, Modest Mouse, etc. For the most part I prefer largely melancholy arrangements (or creepy depressing industrial stuff, lol.)
As for me I like crossover music and any style preferences are not so interesting for me. Such feature of crossover originality and brightness makes me feel happy.