well they are $100 different... the Q9550 is the better CPU, maybe not for gaming, but 2.8 stock for a quad is no slouch. if it were me I would get the E8500 and put the $100 you save towards a better video card
The E8400 processor is $15 less than the E8500 and gives about the same performance.
The E8400 processor is $15 less than the E8500 and gives about the same performance.
You've got to remember that, even now, clock speed is still king with gaming. That E8500 will easily reach 4ghz and beyond overclocked, which won't bottleneck on any card you throw at it.
Prices on quads have dropped enough now that it is worthwhile to go ahead and get the quad