Speaking of Steve Vai (kind of), one song of his that I've always loved is The Audience Is Listening (7.6 MB MP3). It's such a fun song, and I think non-musicians can appreciate it too. Fun trivia fact: He tracked down his real eighth grade teacher to play the part in the song.

It's a really fun song to play along with on guitar too. I've always enjoyed sitting down with the CD and trying to keep up with him, but there's parts I always have to skip (like that fast syncopated clean part right at the beginning, and, oh, pretty much any part where there is guitar). As part of my little rediscovery of the instrument, I decided to learn the whole song. A bit ambitious, of course, but it's the same way I've gone about re-learning piano — I'd pick songs that were beyond my level (To Zanarkand, various Tori Amos songs) and just attack them slowly until I can play them. The results are usually not what I'd call "successful" — I don't think I've actually managed to learn the entirety of any of those songs — but I think it definitely does help somewhat, so it's worth trying.