well, you got an idea - linux is not a gaming platform, even though some games are ran much smoother with openGL support (RTCW, Quake, UT - they have linux ports), as for other games there is winex project at http://www.transgaming.com
that allows you to run some windows games on a linux machine and the list of supported games is impressive (it is still growing), and it takes effort and resources to setup winex on ones system (it might be confusing to compile the winex from CVS snapshot, also $5 bucks a month subscription fee for a precompiled binary is not that bad + you're making sure that more games are "ported" to linux
). As for surfing and chatting I guess it is no different than other choice, but it is more security oriented (no buggy, insecure IE here, minus annoying viruses, but don't get fooled that linux is immune to internet's nastiness - there are linux-oriented "surprises" around the corner, and if you are careful enough you can avoid them as much as possible). Have fun.