Is this a good gaming rig ? 10 PTS to BEST ANSWER?

Even if you don't need to play on max settings you will.The 5850 is an excellent GPU which can handle a lot of games on max settings (including the games you mention).A GTX 560 is sure better but there is no need to upgrade as you ask if you don't want high settings on more demanding games.And the rest of the system is very good for gaming.Hope i've helped.