I used to have ME. It was a nice OS as far as stability, and there were a couple features I was happy to see. But I really don't think it was worth the $90. It was more like Win98 Third Edition (or Win95 Fourth Edition). I would almost bet that even a couple Win98 Service Pack updates could have accomplished the same things as WinME.
Windows 2000 was the first major upgrade since '95, and I fully think it was worth it. It's memory and HD management seem so much better that the 9X kernel. XP will hopefully be worth it too. I've seen XP, and it's actually a decent OS, if you discount the preschool interface.
---Skorpion