I've used XP for the longest period of time and that's because it's awesome. Windows 95 and 98 were OK, but Windows ME was just god awful.
Win '95 because it has Shutdown MS-DOS. Don't know other such OS's well enough to prefer them. If you're going to get picky about "Well MS-DOS counts as its own OS " . . . then Win XP. Maybe.
Well... Mac OS X (10.5, specifically) On the Windows side I recently installed Windows 2000 (via VMWare Fusion). I liked it so much that I ditched my XP virtual machine. Most of the functionality/compatibility of XP with much less overhead. Plus it has the Win 9x interface, which I prefer over XP/Vista. Downside is that, according to my research, it has a number of security issues. But I don't let it onto the internet much, and then only to a few very safe sites, so it shouldn't be a problem.
As an aside, I've been researching OS's and NeXTSTEP came up during my journey into the past of OS X. There's a 35 minute demo video on YouTube. [yt= NeXTSTEP Demo]j02b8Fuz73A[/yt] This thing was waaaay ahead of it's time. Anywho, does anyone know if it possible to find a copy and if so, is it possible to install it on a standard PC box? I know that after NeXT closed their hardware side they ported their OS to IBM, Sun and PowerPC. It would be interesting to see it IRL.
OS X, 10.3-10.5 I also have been using Ubuntu, which is working well. I never liked XP, I was always more of a 98 fan. Windows Mobile seemed pretty solid to me, and Palm OS was quite useful (is it still around?).
It's possible to get very close to the 9x appearance and interface by playing around with settings in XP. Set everything you can find to Windows Classic style. Windows and buttons style, folder view, Start menu style all can be so set. Tinker with other display settings. MY XP computers always end up looking like they've got a 9X interface, and it's much, much better that way.
Can't say I got a favorite one as all of them can be maddening sometimes. At home I am running Gentoo Linux and BSDs. At school it's OS X, XP, Solaris and Debian Linux.
Vista. Debian or Ubuntu might have been in front except for the fact that I can't play any of my games on them.
As I've only ever worked closely with XP and Vista, I have to say Vista all the way. There's only one program from my old computer that doesn't work entirely well with Vista, but it's about six years old, and it's well past time for me to [-]stop using the bootleg version[/-] upgrade anyway.
The simple fact is, you get a computer that was of reasonable quality from up to a year before Vista came out, now, you could put it on there without a hiccup. Anyone who says otherwise is lying. Had a rough start, but once the hardware manufacturers got their asses in gear and once MS (and every other major software vendor that, much like the hardware manufacturers, ignored MS' warnings as to how different Vista was going to handle things) released a few patches (and, notably, SP1, which makes it smooth as silk), it is a rock-solid operating system.
^ But most people are idiots when it comes to working their computers. And for that matter, technology in general. People just go for the lowest price tag without looking at things like memory and processor speed. My uncle did just that when he bought me my first computer (128 MB, 20 gig storage), which even for 2002 was pretty outdated, and it definitely showed about a year and a half later when I kept getting paging virtual memory messages every other day. When I brought my latest computer, I made sure to do some research about how to avoid those problem, since I know I couldn't afford to downgrade.
As a part time techie, I must say I run OS-X Tiger and Panther. In Windows, XP is the best. Vista is vile IMHO. Some like it though, but mostly not those who have to tech it.
It's upsetting to have someone ask you a tech question that you don't know the answer to. "It doesn't work the same as XP?! IT SUCKS!"
To be honest, a lot of your comments on Vista that I read here helped me pick out the computer I have now. Namely in getting more RAM and sacrificing storage space if I needed to. I got a computer with 2 gigs of memory, and even Movie Maker, which I have loathed on the last two computer I owed, works like a charm (for now, at least. I'll give it another year before it starts crashing, but I admit I had the bare minimum RAM needed to run Windows beforehand, much less movie editing software).