If "played with" counts as "used," then I go all the way back to 1.0 (or maybe it was 1.01). Also played with OS/2. I always had a "play machine" in my shop at home, so I could try anything new that came along. When IBM foisted the PS/2 upon us, we bought two of them at my company -- and never, ever, bought another IBM PC. Non-IBM PCs regularly came with Windows disks included. I always snagged a set if there had been an upgrade, but usually somebody in Accounting would peel the labels off and re-format the disks for general use.
Windows 3.0 was the breakthrough, and almost, almost, got it right. Windows 3.1 was the winner, then, of course, Win95. I have owned and played with at least one copy of every version of Windows since the beginning. Just for fun, the same is true of MS-DOS, clear back to when it was PC-DOS, and even Apple DOS & CP/M before that.
It's been a long, fun ride.
Regards,
Russ