I like steam though, none of that "only can install it on so many computers" crap or installing rootkits. Can download it as many times as you want, on any computer. The games on there are cheaper than to buy in a shop, at most you'd only have to pay 30. Special deals come along and allow you to get games for the fraction of that. The only gripes is that they don't easily allow you to play them offline, and that they force you to update the game. Still, to me it's a step in the right direction.
I am wary of pirated games because the cracks used will disable things like online play etc. I also can't apply patches to them.