Great series! I worked a lot with both cpu's and always thought the e8400 was the beter gaming CPU because of the higher multiplier. In these days I thought dual core was enough, but no longer today it seems. Maybe if the motherboard could overclock thuis e8400 it would have been closer.
If you are looking for ideas: how about a contest by getting the most out of a dell Optiplex 755 sff or a HP dc7800 sff. These computers are out there A LOT for almost free, but not easy to get them to play games on.