Intel i7 2600k or i5 2500k for gaming?

if it is only for gaming go with the i5. games dont use HT.

For games the i5 is the best, but for desktop apps the i7 is much better.

Most games support up to only two threads of execution. Therefore the 4 extra "virtual" threads you get with the i7 2600k would be wasted.

Most people recommend that you use the i5 2500k if you game, and i7 2600k when you use heavily multi-threaded applications such as video editing software.

No difference in games

Gaming implies using the i5 2500k, nothing more.

+1 for the 2500K. 2500K is the best you can get for gaming.