CodeSMART

To add all the Visual Studio features that Microsoft got

CodeSmith

Code generation

CodeWright

Text Editing

Desktop Sidebar

Provide you with instant access to some of your most important daily information

Dundas WebChart

The absolute best chart control I've seen

FogBUGZ

Bug-tracking

ieHttpHeaders

Show you the HTTP Headers IE are sending and receiving.

InstallShield and Wise

installer creation

MindManager

Brainstorming

Nant

build system

NDoc

documentation creation

NUnit

TDD fixtures and test harness

Reflector

Spelunking

RegexDesigner.NET

Regular Expressions

RoboHelp

End-user documentation

XMLSPY

XML editing