Sure, but your CPU will limit the card from being used in full in a lot of current games. Not sure if it will be an issue in the specific games you mentioned though.
Another upgrade that would help for gaming and in general and is very easy to install is adding more RAM. RAM is pretty cheap these days. You can double your RAM for $25.http://www.newegg.com/Product/Product.aspx?Item=N82E16820148163