For us its usually Hip Hop or Rap. A lot of good rhythms there depending on the mood, or to create a mood:
LL Cool J - Doin It, Hey Lover, Loungin
Missy Elliott - Pussycat
Kilo Ali - Love in Ya Mouth
P Diddy - I Need a Girl
Dead Prez - Mind Sex
Salt-N-Peppa - None of Your Business
Ludacris - Whats Your Fantasy
Just a few but they work for us!