Is this a good gaming pc?

this looks to be a pretty good computer build.. I'm guessing your collecting and building it yourself? the only things I would suggest you change, and this is fairly necessary. the 400w power supply should be at least a 650 if not a 700W to accommodate all the power that will be used. Also, I would swap out the 9500GT for at least a 9800GTX+ or even go for the 200 GTX series. The 9800GTX+ run at about 120 or so right now and they are mively better, like on par with the 200 series. GREAT CARDS! and the 200 series are a bit more. but other than if you want better sound you can always upgrade to a stand out sound card later on.