So for me, it depends solely on what I'm about to do.
For Cardio based stuff, I listen to Shinedown - Sound of Madness (The whole CD) in reverse order. That a way it starts out a bit slow for your warm up, gets faster but still has a couple of slower songs in the middle to help you catch your breath, and ends with a couple of very hard songs to pump you through the end of the run.
For like weights and what not, I like to listen to Greenday, Taking Back Sunday, and other punkish stuff. Seems to help push you through just one more set of reps everytime.
For Cardio based stuff, I listen to Shinedown - Sound of Madness (The whole CD) in reverse order. That a way it starts out a bit slow for your warm up, gets faster but still has a couple of slower songs in the middle to help you catch your breath, and ends with a couple of very hard songs to pump you through the end of the run.
For like weights and what not, I like to listen to Greenday, Taking Back Sunday, and other punkish stuff. Seems to help push you through just one more set of reps everytime.