[tvorryn]

Team Fortress 2 and DOTA 2 are the ones I know of.

http://en.wikipedia.org/wiki/Team_Fortress_2#Free-to-play

http://en.wikipedia.org/wiki/Dota_2#Free-to-play

[chmike]

One can exchange items, but not sell them. There is no money account in TF2. So I don't see any relation with a real life economy.