Linux. On an nvme which is a disadvantage 'cus Windows likes to overwrite it (and the boot loader) so I can't do dual boot. So if I wanna game, I have to take the side panel off, take the graphics card out, swap the linux nvme for the Win10 nvme I have and do the reverse.
Advantage though is I can boot between them without doing anything other than swapping the drives.
I tried dual booting between Linux / Windows using seperate sata 3 SSD's and Windows would keep corrupting the Linux one. Having to use a pendrive to boot a live CD JUST to fix GRUB every time I want to use Linux became a pain because I would use Windows sparingly and Linux for my main OS.
Then there was the system clock issue but that's another story...
tldr: Linux for everything but gaming. Win10 for gaming.
I won't even go on this site, let alone any banking site etc using Windows. Windows 10 is like installing spyware as your OS. Cortana, which can't be disabled has been found to keylog you automatically for example. You are not allowed to view links.