Don't forget the lightweight xubuntu distribution, which uses the xfce window manager. It is nice and fast. It works nicely on older machines with less resources.
Anyway, a friend of mine can get me a cheap mac(prices are unbearable outside of the us because of shipping and resellers adding up to the price) so I'm going to get pretty close to OS X and i know that its good, but like that guy i might choose to dual boot and have the OS X just there if i need it.