Initially, I wasn't going to waste my time on this survey. But ... after reading some of the replies, I had to throw my two cents in.
You can't beat win98 SE. It was and still is the most stable OS (aside from MS-DOS, of course)
Like Bones92 (and several others), I used to feel that 98SE was the best op sys. I loaded it on dozens of my friend's and coworkers computers, when their Win95 systems crashed, or were simply running bad. It was definitely the best for it's day!
I stuck with 98SE way past the release of ME and past XP. I loaded it on a new system I built well into the XP era. (AMD 1600, if I remember correctly). It was a lemon.(or so I thought) Every couple of months, the system would start acting badly, and I would reload the OP sys. Win 98 of course. Finally after about 18 months of problems, I went out and bought a complete factory loaded P4 2.6GHz System with XP Home edition on it. Ran great.
Some time later, a close friend (on a limited income) needed a computer bad. I told him that my old system was a lemon. Didn't care, it was better than nothing, if he could borrow it. I said OK, but loaded XP professional on this lemon before delivering it. To make a long story even longer, He used the system for a couple of years with no problems.
My conclusion, and the moral of the story is this. Always use the OP system that was prevalent when the hardware was built. The hardware designers test and optimise their boards for the current OP systems. My vote was for XP, but conditionally considering the following.
If you still have an old 286 system, load DOS 6.22. If you are trying to set up that P133 system in the closet, use 98SE. With a newer system, run XP. (or Vista maybe)
Anyone agree with that?