2500K is still very excellent for gaming.
If you don't overclock than even, as mentioned, the alternatives (i3's, i5-2310 [yes its real, clocked a tad higher than the i5-2300 and at the same price] and the i5-2400) are all good. At the moment, Intel is on top of the upgrade path with their new motherboards, the Z77's. Just look into it.