I've been using Windows 2000 on-and-off for about 16 years (only third to that frivolous XP and 98) and I am very pleased to say that with the help of all those who have contributed to extending its capabilities, it has now reached the high-water mark of being one of the few OSes to remain usable for everyday tasks 20 years after release!
A few of my workloads now require Vista/7, but most still do not challenge win2k much. No other OS offers such a degree of folder customization, nor the nice, big picture previews in the "My Pictures" template, neither do I get a task manager with CPU/RAM indicators in a blocky, futuristic font. And I've also got the old Windows flag combined with the post-modern Tahoma font. And enter the extended kernel, to run my browsers and some other newer applications.
So, here's to another 20 years for Windows 2000!! scratch that, considering that Windows 2000 was the best operating system around at the start of the millennium, it shall be the best operating system around to end the millennium!!!