I have been around since the days of DOS on the PC and before that C64C's and Amiga's.
Best OS and machine I've used would have to be the Amiga. (Still is, pats accelerated A1200)
But I do love Windows 8. Once I've unlearnt some legacy habits it's very natural and easy to find stuff :-) My 5 year old son jumped on and he's away.
Boot time is great and for the older stuff the desktop is still there :-)