My experience with Vista was that there's little-to-no gain over XP, but with enough annoyance (even after turning off that stupid "Are you sure you want to open Control Panel? alert) that I downgraded to XP again. Just little things not working.

FWIW, at my last job, I got a Windows 2000 PC after spending a year or two on XP. The only feature I actually missed? Hitting windows-key+L to lock the screen. I am, apparently, a cheap OS date.

(I would say get a mac, but to avoid the mocking, I'll just say: Install Gentoo Linux!)