What OS version should I install on my computer?

I am interested in installing macOS/OS X on my Desktop PC.

The specs are:

CPU: Intel Xeon E3-1270, 3.4 Ghz GPU: NVidia GeForce 710 RAM: 8192MB (8GB) Motherboard: Gigabyte Ultra Durable: H61M-S2PV REV 2.2 WiFi Card: TL-WN823N I don't have a mac. What OS version can I/should I install?