Windows 7
I really like the new Windows. Install took 15 – 25 minutes and boot took 30 seconds. Everything works right out of the box except my Prolink WG2000/R USB Wifi adapter. But that’s an easy fix, there’s a Vista driver for that device on their official website. Just download & install.
There’s one tiny problem though, I can’t dual boot with Windows XP but my files are still accessible.
Problem aside, I managed to install Google Chrome, AVG8 Free & No-IP DUC. All works flawlessly. Maybe tomorrow I will install FF3 & some games. 
UPDATE 13/01/2008
Managed to add WinXP to Windows 7 Bootloader using EasyBCD.