Vista in my opinion. Lots of stuffs in it that makes it the worst for me ,however 2000 was not good either. I can't remember the name of version they created but took it down quickly, it was a mixed of 2000 and Vista, horrible.
You're probably thinking of Windows Me. Windows XP can probably be described as a mix of 2000 and Vista since it was developed in between those two versions but it had a long life and most people don't consider XP to be a bad OS.
Also, I reckon 2000 was quite a good OS so I'm surprised to see that it's been mentioned several times in this thread. It was remarkably stable and ran reasonably well on low spec hardware. I used it for a while on my old laptop but had some problems with connecting to my wifi network so I switched to XP instead which is currently my favorite OS.
Worst for me was probably Windows 7 which came installed on my netbook. But that's probably got more to do with my netbook's low specs and the fact that it was the Starter Edition which didn't even let you change your own desktop background (although there were third party programs which removed this restriction). Never used the normal edition which I've heard is quite good.
I also never liked Windows 8 because of the interface and the fact that it runs so slow on a computer which has better specs than my XP laptop.
98 SE was a great OS for a while but it was very crash-prone and no matter how many times I reinstalled it, it would end up BSODing after a few months. Still, it was my favorite one until XP came along. 95 is a bit too old to make any meaningful comparisons with modern OSs but I remember it being nice back in its time. Everyone hates Vista but personally, I found it to be quite average and not particularly bad although I only used it for light tasks. I only used Me for a few days before switching to 2000 and then XP so I can't really make any judgements based on that but I remember it being very similar to 98 SE.
