Find Scott Hanselman's 2006 Ultimate Developer and Power Users Tool List for Windows here:

http://www.hanselman.com/tools

Who is Scott Hanselman eh? Err.. I don't really know but the tools that he lists I know (well, some of them at least)! From his top 10 life/work changing utilities I am already using 5 (Notepad++, Lutz's Reflector for .NET, Google Desktop, ZoomIt and various other Sysinternals tools) and I am going to give his other suggestions a try as they sound like they're going to be equally super cool!

Put simply these are tools that you cannot afford to leave home without!