I'm about to get a new system and I wanted to make sure I have all of the Vista tweaks I was expecting. While I'm at it, I'll update mine.
TweakVista for improving my experience in Vista.
Script Elevation PowerToys for Windows Vista from July 2007 TechNet including the CmdHere, CMDHereasAdmin, and the PowerShell equivalents.
Since I'm a power TabletPC user I also like Microsoft Experience Pack for Windows Vista giving me Media Transfer, Ink Crossword, Equation Writer, and Ink Flash Cards.
I also like the Ink Desktop.