Well there you go. If this is a gaming machine AMD is certainly the way to go. AMD has been a stronger perfomer than Intel in the gaming sector for quite some time.
Another thing to think about right now is cooling issues. AMD is much easier to cool than Intel at this point. The new Prescott processors are having very serious issues with heat, to the point that people are calling them "Presshot". Also, the newer Prescott processors added a longer, much much longer, pipeline. It's gone from 20 stages in Northwood to 31 stages in Prescott. What this means is that it takes longer for instructions to get to the right place. The Athlon64 has 12. The difference is that Intel can run thier processors at 3.4GHz while AMD runs at 2.2GHz. Both are doing the same relative amount of work.
Anyways, there's a really good article over at Tech-Report that outlines all the differences between the Northwood and Prescott cores and then does an very thorough job of benchmarking a wide variety of processors in both games and apps.
http://tech-report.com/reviews/2004q...t/index.x?pg=1