Do you already have the processor? Do you plan to overclock? If no to both, and all you care about is bottom-line performance, settle for an 8700 (sans K), and get you a cheap H310 motherboard.
The motherboard doesn't determine performance (unless you're overlocking); it only determines what you'll be able to connect to the computer (USB ports, SATA ports, RAM, PCI-e cards, etc.). If you don't care about any of that, it's best to go with a barebone motherboard, and 8700.
If you plan to overclock, go with an inexpensive Z-series motherboard, such as the MSI one William linked to, get an K-series CPU, like the 8700k.
Most of the time, gaming performance will be determined the GPU. Saving money on CPU + motherboard and allocating it towards a faster GPU will often net you better gaming performance.