Hi Epirb. For what it's worth, this is my personal opinion.
Of all the Windows 9x series Windows 98se is the best and most stable. Windows ME added some bells and whistles, but on the whole these have been more trouble than worth. Windows 2000 was developed from NT and is really aimed more at the networking user. The only real advantage of 2000 is that along with NT and XP it makes no attempt at compatibility with old DOS based software, and is therefore more stable.
XP was developed from 2000 but is a huge piece of resource hungry software with a lot of gimmicks, some useful and some less so. I use 98se, and have very few stability problems.