What is your favourite Windows version?

Sorry for my bad English, I speak french!
probably when I change computer I will have to change to windows 10, but windows 7 is one of the best I've had until date (and no need to reset auto 180 days I do not, for the version patched)

my first computers were under "Dos" (and Dos v5 was the best under Dos) and I have tasted all windows since!
I have tried Mac IOSX too :(