Scott Hanselman's 2005 Ultimate Developer and Power Users Tool List
Scott blogged and updated his tools collection. there are some I am very interested and can't wait to try right way

Regions AddIn -- in code project

Lutz's Reflector and it's AddIns - luz's reflector of course is the best tool in .net and there are many add-ins now...
Lutz Roeder - The maker of Reflector also makes Resourcer and inspired the Reflector Add-In community (complete list).

Application Profiler -

ieHttpHeaders - collecting IE httpheaders send/request - mandatory to have

Google Portal - personalize your own portal on internet.

CodeRush - another refactory tool like Re-sharper..

---------- some other tools I found --- -- code template addin

RUnit - an NUnit test runner for ASP.NET - nunit extension to show results in web

Validation Framework   - validation parameter with attribute.