Tchaikovsky's 1812 Overture seems very inspiring to me, but I'm sure it does to many other people also. I can't really think of a song which uniquely inspires myself..
Funny, I was just thinking about the 1812 - it was my warm-up music when I was using my exercise bike. The long slow build-up is ideal to warm up to and then I'd be ready to sprint flat out at the climax when the cannons start going off.
Once warmed up, I'd stick a different CD on and alternate between loud, fast tracks and slower, quieter ones. Ride hard for the loud, fast ones, recover in between. I'd do 45-90 minutes of that followed by a 5-10 minute warm-down.
I'd ride a loud track so hard that my legs would be nearly packing up by the end of the track. At first, it would take less than half of the following track to recover, but recovery times got steadily longer as I tired. I'd usually end the session when I wasn't properly recovered in time for the next hard effort.
I did a whole winter like that once and started the following spring fitter than I'd ever been before, but desperate to get back on the road again!