What song gives you that extra push to finish your workout?

For me it's T.H.E. (The Hardest Ever) by will.i.am ft. Jennifer Lopez & Mick Jagger. When I'm getting tired or need to get through a challenging exercise, I turn this song on and it gives me the extra push I need!!
I could use more upbeat songs like this to keep me motivated! What song(s) gives you that extra push to finish your workout?