from a gaming standpoint, the 3ghz e8400 is faster. if you'll be using adobe creative suite or video editting software, then the quad core q6600 is the better choice. i'd skip the e8300 since it's only $50 less.
I am posting 3 different specifications for the same computer and I would like you to tell me which one is the best to buy. .
Dell XPS 630
Black Bezel Chassis