If truly You will use it only for developing with GLBasic use Win7 (as You don't need all that fancy stuff like DX12 support, multiple desktops, and so on).
After checking Win10 little after was released and seen all that crap with updates, spying tools, strange performance problems, I sticked to Win7 & 8.1...
Now it's better but still there are some issues that are annoying (not everybody encounters them, e.g. background updates causes random restarts) so probably safest option would be to use Win7 (if you don't have Win8.1), yet newer system means better use of multi-core CPU (specially those from AMD), and so on...
But there is a catch, if in future You will plan to develop some UWP base app/game, write something in VisualStudio, then Win10 would be better even with it flaws. Not sure how does it applies to popular game tools like UDK, Unity..