Deponia: The Complete Journey FREE
Head over to Humble Store to get it.
This game is awesome but runs like shit on PC, if you can cope with bad framerate (locked at 30...) get it and you will love the story! Available on Playfield (seems to be a new store!).
This is a really low price for a fine game - only €6 for The Complete Edition. Click here to check out this sweet deal.
Just in time before GTA V release, you can get all Grand Theft Auto games (GTA IV Complete, GTA 3, GTA Vice City, GTA San Andreas)! This offer seems to be USA only but I bet if you manage to buy it in Europe somehow it will work jus fine on Steam. Check it out on newegg!
Mafia II Complete Pack is now on sale on GMG. The game goes for a little more than $9 and is Steam redeemable. I always liked the game even though it was not entirely open world like Grand Theft Auto games. Anyway if you like mobster games you have to play this. Use the coupon: GMG20-GGN5D-FC3NA.
You can now purchase a classic game on Good Old Games for $15. The game of course has no DRM like all GOG games.