You know what.. back when ME was out... it wasn't the OS so much as being the problem... it was the drivers.
ME was kind of, but not quite, compatible with WIN98 drivers. Because of this, few hardware manufacturers bothered to develop ME drivers which forced people to use 98 drivers. THIS is where the problems started.
ME was supposed to be Microsoft's 'home' users' upgrade to 98, just like Win2k was supposed to be their 'commercial' users' upgrade to NT. Hardware manufacturers already knew the Win2k was VASTLY superior to ME on almost all accounts, and when Microsoft finally caught on, they opted to 'file away' ME and focus on a 'home' version of W2K... which became WINXP Home.
Yes, MS introduced some new features into ME such as recovery and backup utilities.. and I suppose this may be useful to some... but I've always turned those features off as they are more intrusive than they are worth. The few times I've used windows restore on others computers resulted in less than anticipated results. But still, I firmly believe that the issues with ME wasn't the OS itself.. it was lack of hardware support.
Because of this, I vote Vista for WORST MS O/S OF ALL TIME.