I just did a budget build, got everything except my video card power supply and windows for $228 out the door. With a 8800gt I can play new Vegas at 1280x720 at ultra settings and stay above 30fps all the time.
Mind you that the g620 is faster then my g530 and the gts250 is faster then my 8800gt. Depending on your Res you should get good performance. I went the cheapest route on the CPU because I'm getting a 2500 i5 in January
Web browsing is super quick, everything feels very snappy, overall for a budget build under $300 for the whole tower I'm very happy with what I got.