Here is a compilation of very useful utilities for VS 2010 and VS 11.
Note: Utilities with an asterisk (*) beside the name are not available to VS 11 yet.
CLIArgs Made Easy
http://www.ricardosabino.com/?p=214
CLI Args Made Easy (Command Line Arguments Made Easy) is an add-in that allow you to change the command line arguments of the startup project very easily by adding a combobox in the toolbar. It also saves all the arguments you insert for future use.
Debugger Canvas (*)
http://msdn.microsoft.com/en-us/devlabs/debuggercanvas.aspx
Debugger Canvas is a new user experience for the debugger in Visual Studio Ultimate. It pulls together the code you’re exploring onto a single pan-and-zoom display. Visual debugger and multithreading debugging goodies.
Productivity Power Tools (*)
http://visualstudiogallery.msdn.microsoft.com/d0d33361-18e2-46c0-8ff2-4adea1e34fef
A set of extensions to Visual Studio Professional (and above) which improves developer productivity. Very useful enhanced scrollbar, vertical tabs, quick find files, searchable references and editing tools.
ReSharper
http://www.jetbrains.com/resharper/
With unparalleled support for C#, VB.NET, XAML, JavaScript, XML, HTML, CSS, ASP.NET and ASP.NET MVC, including comprehensive cross-language functionality, ReSharper will help Visual Studio users write better code, easily examine and refactor existing code bases. A must have for anyone who’s doing C# code.
Visual Assist X
http://www.wholetomato.com/
Read, write, navigate, and refactor code FAST with more than 50 productivity-boosting features for C++/C, C#, VB, ASP, JavaScript. A must have for anyone who’s doing C++ code.
VisualHG (*)
http://visualhg.codeplex.com/
Mercurial Source Control Plugin for MS Visual Studio.