Depends. If it's an upgrade from a prior lga1151 cpu, then the i7-7700k is top of the line. If it's just a choice, and op is also going to get a mobo, currently there's only the Z370, then a combo with 8th gen would be better. But the i7-8700k lga1151v2 cpu is not going to work on a lga1151 motherboard.