Excuse me? 2000 was the last great OS Microsoft ever made. They should have stopped there. It was NT in its prime. It was also, in my opinion, the last Windows OS to act like a computer instead of a toy and insulting my intelligence with dumbed down interfaces. It felt like Linux feels now. It feels like you're in control of your computer.
XP was just 2000 with a toddler-esque Fisher Price skin.