Bill Gates is a dirty fascis...
Oh, wait. Non-political.
If you network into a domain server, don't get Home. If you only have a small home network, Home is fine. W2K isn't supported by GS3, yet it is surprisingly similar to XP. The biggest beef I have with W2K is it's extremely long boot time. It's also older, has a smaller installed base and may go obsolete before WinXP, though that's debatable. Certainly WinXP will get more attention from audio developers (as shown by Tascam).
Bottom line: XP Home for home networks and standalone systems. XP Pro for more intensive networks and if running a domain server. W2K if you already own it and really don't want to spend more money on another OS.