The Nvidia 6150 is a pretty low end card, it should play HL2 / CSS if you force them to direct x 7 mode and use a low detail graphics and a low resolution. Its really not a gaming graphics card. You could play all the old C&C games, that card should play up to generals fine. Unreal Tournament (the original) will work well. What type of games do you like? Most games released in 2004 or before than should be playable.