I have played several new games on my 1 1/2 year old computer with a 2.6 GHZ celeron, INTEL motherboard with a 845GV chipset and it works fine, not one problem.
The graphic card market play's a huge role in gaming today. Pick and choose a graphic card wisely here, they are ever expanding, and compitition is HOT. It feels like there is a better one on the market ever month. Don't get me wrong though, a computer 2 years ago ment for gaming, will have a hard time playing the graphic rich games of today, but it's not that they won't!! it just might be not as fast or as stable. Today's Graphic cards are the gate keepers and hold all the keys too unlocking a computers gaming capabilities.
I would strongly suggest spending the money on a very good motherboard which has a top of the line CHIPSET, and has the capabilties to be upgradeable later, so you can keep up with the times as much as possiable. But get ready, who knows what there will be as far as hardware and software goes, that pride and joy of a machine you just built, a year from now, I hate to say it, will be out of date. So get the best you can now, so it won't be so bad later. Your flip side to the reality side. Newt