as the thread title states which will be better and more future proofed the i5 2500k vs i7 2600k? the build i would be putting them in would be mostly for gaming so which one is the better processor for the long haul?
The main difference between the Intel® Core™ i5-2500K and Intel Core i7-2600K is hyper-threading which allows the Intel Core i7 to run up to 8 threads. Right now very few games will take advantage of more than 4 threads and those that do give very little performance increase for the extra threads of support.
Now I have a friend who is a professional programmer; when I ask him about thing like this he said that he really hates to try to program for for multi-threading as it hard to break the appications up to be taken by other cores.
So for the forseeable future support for additional threads over 4 will most likely stay the same. So you should be safe saving the $100 and going with the Intel Core i5-2500K unless you are also doing some video editing or other heavily multi-threaded applications.