I used to be pirating games while I was like 14, like CS:S or Half Life 2, Garry's Mod 10, or even Fallout 3.
Now look here:
http://steamcommunity.com/id/essgeeeich/games?tab=all
Got CS:GO, HL2 and Fallout: New Vegas, plus a lot of more games I gained winning giveaways and from public giveaways.
For instance, Defense Grid was a Logitech giveaway a couple of months ago.
Metro 2033 had a Facebook giveaway on the Metro's page.
Magicka's been gifted by a friend.
Multiwinia, Europa Universalis 3 and Alien Hallway come from a one-winner giveaway.
I've been even gifted an account of another user who doesn't use it anymore, which has CS:S, L4D2, HL2:DM (AMD promo has ended) and DoD:S.
But actually, the money I did really use for the games I own, have gone just to Garry's Mod, HL2, TF2, Fallout New Vegas and Ultratron.