Title says it all. It can be any song you want. Also, please write what you base your desition on- like recognizability, creating emotion and so forth. I think the theme of a wrestler is really important, both as part of a spesific wrestler's gimmick and to allow the crowd to mark out when they hear the first couple of seconds of the intro- read: glass shattering, IF YOU SMELL etc.
God knows there are a lot of ****ty themes nowadays, and a good theme song could do a decent job of getting more over- read: Barrett, Cody, Ziggler.
Anyway, my choice would probably be Blinded in Chains by Avenged Sevenfold. The drum intro is awesome, and the fast- paced nature of the song could help cause a reaction. The intro is also quite long, so it takes while before there is a substantial change of pace.
The song: http://www.youtube.com/watch?v=EPpLVdbVXFI
Not sure if this has been discussed, but I couldn't find a thread on it. Feel free to lockhammer it if it has.