For gaming?
According to Tom's...
"CPUs priced over $240 offer rapidly diminishing returns when it comes to gaming performance. As such, we have a hard time recommending anything more expensive than the Core i5-4690K, especially since this multiplier-unlocked processor is easy to tune up to 4.3 GHz or so with the right cooler. Even at stock clocks, though, it matches or beats the old $1000 Gulftown-based Core i7-990X Extreme Edition in our benchmarks.
We have seen a small handful of titles benefit from Hyper-Threaded Core i7 processors, though. Because we believe this is a trend that will continue as developers optimize their software, we're including the Core i7-4790K as an honorable mention, now selling for $340. In a vast majority of games, the Core i7 won't demonstrate much advantage over the Core i5. But if you're a serious enthusiast who wants some future-proofing and values highly-threaded application performance, this processor may be worth the extra money."