Q: fedora core , vista , tiger mac, panther mac , leopard mac ,xp , windows 2003, or snow leopard
A: If you are not a gamer then it would be Leopard as Snow Leopard (10.6) is still in developer stage. Panther 10.3 is about 4 years old and was superceded by OS X 10.4 If you are a gamer then probably XP. Fedora core if you like Linux and like to tinker with the internal code. I wouldn't touch Vista if you paid me and neither will Intel Corp. Windows 2003 is NOT a desktop operating system - it is a server OS.