CS is NOT the "best" online game, it's not even a game, it's a mod for a game. It's just the mostly played mod/game on the net, because it's so easy to play it, and servers are everywhere. In fact there's probably more servers for CS on earth, than there are viewable stars from your garden on a clear night sky :o
I personally hate CS, hackers and cheaters spoiled it, and I don't trust anyone in it now, regardless of what server side anti-cheat progs are running =/
By the way, anyone here tried AO? (http://www.anarchy-online.com)
I play that quite a lot, and it's a great game to play, all in lush 3D too =).
Hmmm, the BEST online game? Tough one to answer I'm afraid, but I'd personally respond with Natural Selection, which is another Half-Life mod. (http://www.natural-selection.org)
Aliens or Marines, pick a side and get this: you actually need barins to win it =D, so go away CS players =P
http://www.sepherion.co.uk/images/wufflez/Wufflez.jpg