Q6600 or e6850?, q6600 offcourse.
But dualcore is still good.
game producers have to make games which are playable for most people, mostly nubs. And nubs run conroe's at stock speeds, for example 2.13ghz. Then a 3.6ghz dualcore should be good enough, even for future heavy games which are quadcore optimized. But 230 euro for a Q6600 is just a steal.