The Corsair, or a Seasonic FOCUS or PRIME ULTRA 650 Gold. EVGA PSUs are also getting excellent reviews. Any of these are great so at this point, price is often the deciding factor. I got a Seasonic Prime Ultra 650 Gold for $106 last year (before the Trump tariffs send the price of computer parts climbing) and it's an impressive PSU, both in specs and performance.
650W to 750W, minimum 80 Bronze efficiency, compatible PCIe power cable connectors for your GTX 1080 - it depends on the model, 1 x 24-pin 1 x 8-pin ATX connector for the M/B.
My advice make a research of your own. And don't cheapskate about it especially if you want to O/C.
Use sites that know some stuff about PSU's and have some legit reviews like http://www.jonnyguru.com, Aris Mpitziopoulos here at www.tomshardware.com has some great reviews also...... and then use the pcpartpicker.com to compare the prices of your findings.
If I had to choose between the 80 us$ no matter what, I would pick the Corsair CX650M
it has 2 x PCIe 6+2-Pin Connectors.