I've been having good luck with the Q6600, so far. I haven't really played PC games since Wing Commander 3 was new, so it has been an eye-opening experience.
Anyhow, I got a real bargain on a co-worker's left over PC parts, including a modular 750 ps, a Gigabyte GA-G31M-ES2L mb, 4gb ddr2, a 160gb hdd, and a decent NZXT case to put it all in. I added a cheap optical drive, Win7 SP1, and 2 240gb ssds (another new thing to me, had to try them out, amazing how cheap it all is now). All of this came together at the same time that I got an unbelievable deal on a nib Asus STRIX-GTX960-DC2OC-4GD5...I never intended to get such a powerful card, it just fell in my lap and I couldn't pass it up.
Thus far I have been mostly reminiscing with games past, like Civilization 3 and Sins of a Solar Empire. The machine has no problem running these, of course. I have been playing Starpoint Gemini 2, which is coincidentally like Wing Commander, with all of the video settings set to maximum, and the only problem that I had was my 6 year old wireless mouse cutting out during combat. I fixed that problem today with a new G502 mouse...it's crazy how much I have missed out on in the years in between, but now I get the pleasure of catching up with the rest of the world.
I'm pretty confident that this machine is very capable of running a great deal of games, I only hesitate when the game requirements call for i5/i7 processors...but that still leaves a lot of games. Overclocking sounds interesting, though. That may be something to try when I get bored with what I've built...