for gaming the i5 is currently the best goming cpu intel has but the 1366 socket is the one to get if you can but for your uses i would reccomend the
gigabyte ud4 p55
ati 5770/5850 depending on budget
4 gb cas 7/8 1600 mhz ram,g.skill ripjaws a good set
well modern gaming isn't as much cpu limited as it is graphics limited its bout a 40%/60% split favouring the graphics card the i5 is clocked a lil slower but on eqaul graphics terms the i5 system will be less then 15% behind the i7 930 basically no more then 10fps difference where an i7 really shows its muscle with its tri channel memory (dual channel in the i7 8xx series) and its advanced hyperthreading and general higher throught output will be the best on actual productivity situations like rendering and simulations, i dunno for sure if you don't do actual work on your pc,but the i5 hits the spot for gaming if you have the means go as high as you want, im just saying for gaming you wont need more then an i5 for least a few yrs
What obsidian is trying to say is that gaming these days is limited by your GPU, not your CPU and that for gaming, a i5-750 is all you really need, as the features of the more expensive CPU's are not useful for gaming.