I have used almost all windows OS's from Windows 95, 98, 2000, XP Pro,
XP Pro x64, Win Vista & Win 7
My favorite OS is Win 95. I really liked it, every OS which came after
that was not as good untill XP Pro SP2, and now SP3.
Win Vista may seem OK if you use it for a long time, but after
installing Win 7 RC, I realized that Vista is the Beta OS, and not Win
7.
Summarizing, Win XP is the best OS which MS has ever made. It is sad
that they stopped working on it, when it clearly is a very stable OS
without flashy stuff which makes it crashy.
Try using office 2007 in vista or win 7, it sucks. It works best in
Win XP - surprising!!
I don't know how long it will take win 7 to be like win XP - as in
stable and usable and fast.