Threads on this subject seem to pop up once a year, so maybe a link to this site should go in the archives.
http://en.wikipedia.org/wiki/List_of...entrance_music
Some awesome choices:
Willie Bloomquist: "In Bloom" - Nirvana
Pat Burell: "Holy Diver" - Dio
Cliff Floyd: Theme from "Sanford and Son"
Tom Gordon: "Flash Gordon Theme" - Queen