I was 9 years old when Windows 95 was released and it was the first major windows version that I had any real experience with. Of course this was back when you could buy a desktop computer for a whopping $3000 USD and it came with a Pentium processor running at 166 MHz, 32 MB of RAM, and a 2 GB hard drive. That was considered "top of the line" back then. Windows 95 was THE operating system to have at the time. I loved it.
When Windows 98 was released, I didn't have the opportunity to upgrade immediately until I got a job working at the school and I pirated one of the CD keys, but by then Windows 98 SE was already out. (woohooo) It was still just a DOS overlay and aside from some extra bells and whistles, like the stupid active desktop and the added hardware support, I didn't notice much of "wow" factor after using Win95 for a couple years.
Windows ME came and went... heh, we all know the story with that one. PASS!
I was able to get a copy of Windows 2000 Professional from the school around the time I was 14 or so. It was the first NT based platform that I had any experience with. But at that age, all I really cared about was playing games and screwing around on the internet, so the additional features that came with Win2K didn't mean much to me. However, it was a nice stable OS and I did enjoy using the NTFS file system for increased disk performance.
Windows XP came out when I was about 16 and I really started to get into computers a bit more. By then, I was already running dedicated servers and what-not. I was able to get my hands on a Windows XP Corporate key (that wasn't locked by MS) through the school. It was great. Windows XP provided a lot of additional features and functionality that was much appreciated at the time. Windows XP Pro remained my operating system of choice up until the release of Windows 7.
Windows Vista came and went.... another joke that I didn't actively participate in for obvious reasons.
Windows 7... what can I say. It's probably my favorite OS that Microsoft has released to date. Great features. Great hardware support. Great functionality. Great use of the computer's resources compared to previous versions. *cough* VISTA *cough* It's just all around awesome. I will continue to use Windows 7 until further notice.
Windows 8. Garbage. Their stupid "metro interface" drives me nuts. Even in desktop mode, it's impossible to use on a desktop or laptop because of the start button being gone. It's an all around pain in the a$$. I have to use third party software to find it even remotely usable. No thanks.