oh great! another OS war!!

well, the closest you\'ll get to a free, stable OS is either linux or freeBSD. but in both don\'t expect to play every game you can get in win* ...PS, vendetta and other games are linux-native, and there\'s tons of ports, also there\'s the win* game emulator, but you\'ll still lack a few games. but if you look for a great,
stable, nice looking (check some screenshots!!), highly configurable free OS, then linux could be the OS of your choice
...also PS runs better in linux :] ...no really, since you compile it from source, it\'s really fast (comparing to the (win*) precompile version!)
about other programs support: well, you don\'t usually run natively some apps (M$Office, Photoshop, Maya...) but there are either great open-source alternatives (OpenOffice.org (or even CrossOverOffice which 100% supports M$Office), theGIMP, blender...), ports (photoshop has an older port), or you can run them in an win* emulator ...let\'s just say that i haven\'t used windows in more then a year and i don\'t lack anything :]
check
http://www.happypenguin.org for latest news on linux-native games
and
http://www.transgaming.com for latest news on the win* gaming emulator and a full (=large!!) list of games it supports
for gentoo (my distribution of linux) check:
http://www.gentoo.orgfor a very simple to install distribution (mandrake) check:
http://www.mandrake.org (or .com)