On my gaming desktop just Windows 10.
On my gaming laptop, currently triple booting Windows 10, Linux Mint, and MacOS Catalina.
My server runs Proxmox, which hosts VMs for Windows 10 (for managing/recording my security cams and a few other things), Linux Mint as my work PC, and Mac OS High Sierra cuz I was playing with PCIe passthrough for a 750 ti. I have a few other OS's running in VMs as well, but they were more for testing a few things than actual use (XP, Arch Linux, Debian, CentOS, Windows Server 2016).