6700k, or better, 5820k. The difference in games might be big on benchmarks, but while you're playing, your FPS doesn't stay at a set minimum, set average, set max, it's all over the place. Meaning you won't be able to tell the difference between the two outside benchmarks, because the FPS in games is fluctuation too often. Intel shoots for 5-10% IPC increase, and for all their new products, you will pay a premium, meaning 6700k is very likely going to be better value (price to performance).
All the best!