I'll hop on the i5 bandwagon too. I actually have an i7-2600k, basically because I was spending enough on everything else the extra ~$100 was not significant to the overall build. But if I were being at all careful with my money today, I'd go with an i5.
As an aside, the reason I went with the i7 was because at the time games were making the jump from using 2 cores to using 4, and I was a little concerned that I'd regret it later. However, hyperthreading only nets about a 30% gain at most, and probably more like 10% in games, so you're looking at 4.4-5.2 effective "cores" of performance, and that's only if the application is heavily threaded. Many times there's a slight penalty for having hyperthreading enabled when gaming.