Is there a Game Boy Color emulator for Lion? Is there a GBC emulator that will run on Lion? I've been in the mood for some nostalgic gaming recently, and I'd love to play some of the games from when I was younger.
http://vba.ngemu.com/
Visual Boy advanced should work on Mac. I haven't personally tried it out, but if it's at all as good as their program for PC you'll be set.
Best of luck