have civ 5 key for steam want game offfers

Have: Key: Unstoppable Gorg, BF3 B2k(DLC), Krater(cbt), Q.U.B.E, Choplifter HD, King Arthur - The Role-playing Wargame, bunch of heroes, Roboblitz, The Ball , Xotic Tradable: Killing Floor, Zero Gear, DogFighter, Global Ops: Commando Libya, Dead Horde, Half Life 2 Plants vs Zombie x2