I have to humbly disagree that XP is MickeySoft's best yet...it's just their latest. Only if you are suckered into believing Microsoft's marketing hype, is it the best. They have been saying that about every new OS release since MSDOS 6.0... if "the best" means going from a working system to a broken one, I'll take a pass.
Just to list a couple problem areas...

Windows XP Gotchas
Windows XP serious security flaws

But hey...you tweak, fiddle, and fix...leave the flying to me