Hi,
There is no i7-7600K, but rather i
5-7600K or i7-7
700K.
Going back to your question, the best CPU for the socket 1151 v1 is the i7-7700K :
Socket 1151 v1 (1xx/2xx series chipsets) : i5-6600K / i7-6700K | i5-7600K / i7-7700K
Socket 1151 v2 (3xx series chipsets) : i5-8600K / i7-8700K | i5-9600K / i7-9700K / i9-9900K
Socket 1200 (4xx series chipsets) : i5-10600K / i7-10700K / i9-10900K