To honor Wayne Gretzky on his 50th birthday, you could go to the various tributes around the web that talk about his passing vision, his hockey IQ, his impact on NHL expansion, or the many other things that The Great One gave us, both directly and indirectly.
Back in the 1990s, Gretzky's influence in the United States was probably at his peak. As far as I can tell, he's the only hockey player to be name-checked in two indie songs, one by Los Angeles-based punk band Goldfinger and the other by New York art-rock band King Missile.
So, rather than sing Happy Birthday to Wayne Gretzky, join me in listening to one song about Wayne Gretzky, the Handsome Canadian Man and another song that compares the scoring abilities of Jesus Christ to Wayne Gretzky (in one line; insert your requisite quote about Jesus hitting a curveball from Major League here).
First, the lesser known of the two -- Jesus Was Way Cool by King Missile (1990). (If you want to fast forward to the Gretzky line, it's at the 55 second mark.)
And the song that has some degree of notoriety, Wayne Gretzky by Goldfinger (1994).
To finish it off, it'd be appropriate to put up a clip of Gretzky's notorious SNL sketch Waikiki Hockey. Unfortunately, it looks like NBC has stripped the Internet of it due to copyright violations. If you've never seen it, picture Gretzky surfing against a blue-screen projection of waves while singing a song about playing hockey in Waikiki.