Where da party bands at?

Any industrial metal remix album should work, although a lot of it's depressing.

NIN, White Zombie, Rob Zombie, Fear Factory, and then stuff like Rammstein, KMFDFM, Orgy, Static-X, Spineshank, Front Line Assembly, Ministry, Depeche Mode, etc...

Andrew W.K. is probably the best party music, and pre-1993 hiphop, like Cypress Hill, Tribe Called Quest, Public Enemy, LL Cool J, De La Soul, House Of Pain, Naughty By Nature, Run DMC, Dr. Dre, Snoop Doggy Dogg(Doggystyle-era).

And, of course, any keyboard-oriented club/dance/techno/house/trance/gabber.
 
I find that Iron Maiden makes for nice party music. Especially after most of the beer is gone, and people start singing along.