I've been inspired by a lot of songs that are Superman related. "Kryptonite" by Three Doors Down, "Save Me" by Remy Zero and "It's not Easy to be Me" by Five for Fighting have found their way into my play list quite often.
"It's not Easy to be Me" I am particularly fond of for its lyrics. It must be pretty tough to be Superman, or to a certain extend, anyone that carries a heavy burden of having high expectation put on him/her. The song sounded a little sad, and I usually like sad songs.