I didn't include betas of these OSes in the poll because that would take up FAR more than the limit of 20 options
If your favorite older OS is a beta, just post it's code name and build number (I.E. Chicago 58s, Nashville 999, etc).
Post your favorite old Windows version and why here, however, if you just want to express your favorite version, and not why, simply use the poll instead of posting, to keep the thread clean.
Mine is good ol' NT 3.51 because it has a great combination of the old Windows 3.1 style interface, however it has a fully 32-bit architecture at it's core, which enables it to run certain programs from Windows 95 and NT4.

Windows 2000, Because it's where Windows XP Began from, It has a UI that looks 80% identical the Windows Me UI, And it's fast on most computers as long as it has more than 64MB of RAM and a 200+ MHz Pentium CPU, I liked using it on Pentium (MMX), II, and III PCs

While I believe technically Windows 95 was the first computer I physically touched and clicked, Windows 3.1 was the one we had in the house and I grew up learning till we got a Windows 98 computer at the beginning of 1999.
Therefore just because of my fond memories of old versions of Excel, Paint, programs like Sokoban, noisy harddrives, mechanical keyboards without the Windows Key, and the overall ease of use of Windows 3.1, I have chosen it.

The only other operating system on the list that I have used extensively was Windows 98 which i used for a whopping 6 years, which always seemed unstable to me and nothing special.

Windows 2000,

3.1 just because it was the first OS I used
and I still play flight simulator and doom on it from time to time

Windows/386 It was one of the more capable hypervisors of its time! And it showed just what the 80386 processor was capable of, while everyone else was chasing the 80286 and its brain dead protected mode.

I'm odd in that I don't have a favorite "vintage" Windows version, I prefer plain DOS if at all possible, which is why I still have an XT beside me as no emulators beat a real DOS machine.

My favourite vintage Windows OS... I guess that would be either Windows 98 SE or Windows 2000. Either way, 98 SE has the most nostalgic value for me.

Favorite vintage OS? Well, it's Windows 95 OSR2 and Windows 2000, because these were the systems which were used on my home computer and I was learning them from the ground up.

I'd say 2000, although on the flip side I wouldn't call W2000 vintage by any means.

2000.

Aside from XP and 7, its pretty much the most stable Windows.
And those wonderful login screen sounds.


Nostalgia

Neither would I, but there's some people who would

Windows 2000 is the only OS that was *ok* to use. We had it in our school with a terrible custom logon script (which was easy as to by-pass) But it was stable most of the time.

I dunno. By most people (including myself) Windows 2000 is still considered to be one of the most stable Windows OS's of all time.

Best of Favorite Old Windows
1.Windows2000
2.WindowsNT4.0
3.Windows98

winderzzz meeee
just kidding
i agree
windows 2000

Windows 2000. That was my first step into computing and virtualization.

For me, it's Windows 98 SE.
When i got my first computer with 75MHZ and 32MB RAM, Win98 was installed on it..
Then i got my 300MHZ Siemens computer, and it had Win98 too..
IT WAS EVERYWHERE!

Nothing against the original poster or anything, but why can't Windows XP and Windows Server 2003 be listed as "vintage"? I mean, they're not only very close to Windows 2000 (which for some reason is listed), but they were from nearly the same time and are therefore almost as outdated today, so why not list them?

Yes, Windows XP may technically be "supported" until April 8th, 2014, but that doesn't mean that it's decent on modern hardware. Even Service Pack 2 was released at a time when 64-bit computing was in its infancy, and when many people were still using Pentium II and Celeron equivalents from the Windows 98-era.

And it's also not very secure in this day and age either - I learned this the hard way, when an apparent security flaw disabled my Windows XP Service Pack 3 installation's Internet connection, taking my Internet Explorer 8 installation with it, meaning that I was simply left without a decent browser for a long time since I didn't trust people not to use the increased market share from the alternative browser as a means of threatening other developers (mainly Microsoft), since I already considered it to be an invasion of my privacy having Internet Explorer listed in that way.

And of course, back then, I didn't want to accept any advice from anyone else either, since I wanted to fix this issue all by myself with absolutely no help from anyone else whatsoever apart from reinstalling Windows itself, so I was left with just about the worst browsing experience ever, thanks to that security flaw in Windows XP (and this was Service Pack 3!).

Finally, after switching to Windows 8 completely, I learned how much more secure the modern versions of Windows are, and that anything before Windows Vista is essentially "vintage" for all intents and purposes. Once it's about ten years of age, it's old, and Windows XP is no exception.

Windows 2000

Windows 2000. It still is suprisingly usable even in 2013.

Windown 95. It was the first OS that I used

Windows NT 4.0 and XP, I think.

Windows 2000. It's betas are good. And it is base for XP. Multimedia, performance, security, good server. It's 2000!

1. Windows NT 4
Windows NT 3.51 with W95 look, without all the webby things
2. Windows NT 3.51
It can run many Windows 95 programs and it's without the W95 interface.
3. Windows 2000
No comment.
4. Windows Whistler
Watercolor rocks!