I think the challenge is to come up with super-hero songs that do NOT 
feature Superman. Being the archetype for the genre, the use of 
"Superman" is more a generic than a specific.

Here are some of my favorites:
You're Really Super, Supergirl--- XTC
Sgt Rock--- XTC
Brainiac's Daughter--- Dukes of the Stratosphere
Comic Book Heroes/I'm Your Superman---Rick Springfield
Comic Books---Debbie Harry
Will Love Find CHastity Rose?--- PIllbugs
Magneto & Titanium Mam-- Paul & Wings (yes, they are 'real' characters!)
Supergirl--- Outer Space Love Project
Sunshine Superman---Donovan

My web-fu is failing me right now, but I know there are a couple of 
decent web-sites with lists to lots of songs about comics and super-hero 
characters.

Joe Field
http://FlyingColorsComics.com