I'm in currently in mourning due to the loss of of most of my music, including my workout playlist. To workout I prefer songs with great beats and lots of variation between the songs. Certain songs are for crunches, some for jumping jacks and some for dancing. Trust me, you want different songs for different types of workouts. I always work better with a song I love motivating me. Music is a big part of a lot of exercise classes and it isn't hard to understand why; time passes so much quicker when you're listening to a song.
A magazine I once read said that Sexy and I Know It is the best workout song. Something about the base that comes in right away, and the drop before the chorus. My Zumba instructor has a dance to it thats fun, but it isn't one of my favorites. I much prefer spanish beats and the new belly dancing song we tried last week.