I like win2k over xp, productivity wise. XP is just win2k with skins for me, basically.

I used linux redhat (7.1-7.2) and liked it as well, consumes les than half the memory, set my swap disk to less half of what XP would need and still ran reasonably stable. But the programs I need wouldnt run on linux, so it's 2k or xp for me.

I wont go back to win 98 (and all its variations). Win 98 never lasted 6 hours without crashing on me while working on some intensive programs.