My ratings (subjective of course):
Windows 3.1 - mainly ok, but didn't like that you couldn't have more than 16 colours (DOS supported 256 colours at the time). 5/10.
Windows 95 - liked it a lot, although it crashed a lot too. 7/10
Windows 98 - liked this too, as long as it was Second Edition. Some tweaks over 95, crashed a bit less. 6/10
Windows NT 4 - wasn't keen on this at all, extremely locked down if you weren't admin. Hell, you couldn't even open the clock to see the calendar! 4/10
Windows 2000 (NT 5) - my fave out of all of them. Basic looking, but it took all of the best bits of Win 98, rolled into an NT OS. Good sense of control over the OS (if admin) and no dumbing down. Even worked well for games. 10/10.
Windows Millennium - absolutely useless. Tried it briefly on 2 machines and it was blue-screen disco on both of them! 0/10.
Windows XP (NT 5.1) - 'twas ok, could still be made good as long as you turned off the dumbing down aspects like the doggy search and changed control panel category view back to icon view etc. 8/10.
Windows Vista (NT 6.0) - this one annoyed a lot of users (e.g. UAC) but I wasn't that bothered. Still have Vista on one of my laptops. 6/10.
Windows 7 (NT 6.1) - a good 2nd place for me behind Win 2000. Took a lot of the good bits from 2000, but chunkier looking. I preferred the more basic look of 2000. 9/10.
Windows 8 (NT 6.2) - Metro had a lot of hate, but I quite liked it as both a touchscreen user and a non-touchscreen user (have used both). Then 99% of the time, it looked like Win 7 anyway. 9/10.
Windows 10 (NT ??) - following the bad press about Big Brother, I didn't bother with the 'free' upgrade. I just stuck with Vista, 7 and 8.1 on my 3 laptops.