Windows 2000 was my all time favourite. It was lightweight, snappy, reliable and clean looking. MS should have stuck with that platform and simply add compatibility with newer tech such as 64-bit, newer drivers, security etc... All the flashy GUI stuff is just a mess now and they keep changing where stuff is. In 2000 everything was the most logical imo. Thankfully you can return to Windows classic but I think they removed that ability in 8.
Now I'm on Linux though, while I enjoy this platform I find it has it's quirks such as lot of things being harder than they should be or stuff is lacking in certain areas. I can't say I prefer a distro more than the other, but so far I like Mint (17). The only thing I don't like about Mint is the "explorer" is sub par such as lacking a decent search (there is one, but it just plops a bunch of icons on the screen without telling you where they are in the file system), and some apps like Kate are broken but in general I don't know if I'd want to go back to Windows at this point. I like the idea of not being at the mercy of a corporation.
Windows ME was a joke, but to be fair, the only time I saw it is when someone had an issue, so the only version of ME I ever got to deal with was ME full of spyware and other garbage. But still, it just felt so unstable. I'd always replace it with Windows 98 or 2000 depending on the system specs. Same with XP, when it first came out it was terrible but mostly because it was put on hardware that was underpowered, so I'd put 2000 instead.
Windows ME was the only operating system I avoided, mostly because I had clients with that OS and their systems always seem to need help. In retrospect, it was probably as much user error as actual problems with the OS.
I'm going to catch hell for this...Win 8.1 Pro. Been running it since the upgrade and it's rock solid. I've even gone through a motherboard, mem, gpu swap all at once and was able to keep going swapping my SSD into it. Windows 7 could never do that without reactivation and a bunch of other headache.
Also a lot of other nice little things that I miss when I use or service Windows 7 systems. DPI scaling is nice on my super high dpi workstation system.
I've heard some people blaming it for recent credit card breaches. Not sure how true that is, but I wouldn't be shocked if it were the case
Malware for embedded XP emerged in the middle of the last decade, using a technique called "RAM scraping." XP has relatively weak memory access protection, so once malware is inside a PC it has free reign to do its business. RAM scraping is how a hacker group stole credit card information from TJX Companies, TJ Maxx stores, Office Max, Dave & Busters, DSW, Heartland Payment, BJ's Wholesale Club, Barnes & Noble, and Sports Authority.
Windows 7 is pretty awesome. I stuck with XP until 2011, but 7 is better.
I used Windows 8 on a Surface Pro 2 and didn't like it. I'll probably stay with 7 for the next few years. I really have no complaints with 7.
X2Win7
I've never had to re-install to fix a problem. XP is a close runner up, but it clogged up over time.
I used Windows 2000 way longer than I should have. Never had a legit copy of XP. I didn't like using it, but I did.
I upgraded to Vista (Tech Previews and RTMs) ASAP, then I got a 3 or 4 free copies of Vista Ultimate from the Big Rewards thing. (play games, get points, redeem for Microsoft stuff). I used Vista almost exclusively till 8 came out.
I never wanted to buy 7, because I never saw much of a need to upgrade. It was a slightly upgraded Vista with a new name so the haters would forget that it was just Vista with a new name! I got a Technet key from a friend and used it for less than a year, when I switched to laptops.
My first one (low-end Celeron-powered Toshiba) came with 8. I didn't have a problem acclimating, but it really came into it's own with the 8.1 update. My next two (Lenovo's u530 Touch and current Y50) both shipped with 8.1.
I guess I'm the odd man out. I like Vista and 8.1, didn't much care for XP and didn't see a need for 7. Everything 7 did, could've been done in a SP3 for Vista. People hated these two OSes so much that nobody bothered to actually look at them for their own merits.