Visual Assist
Visual Leak Detector

Russian readers can also check PVS-Studio blog PVS-Studio

Indent Guides
Image Watch

CodeRush and Resharper, CodeRush is really good but needs a lot of memory

Visual Assit X
Cpp check integration

For C# - imo, nothing better then ReSharper & Reflector

Something a little out of the box though -- With PowerSpolit and Nishang PowerShell frameworks being as robust and extensible as they are, this VS extension may be of interest to you.

PowerShell Tools for Visual Studio - PowerShell integration for Visual Studio
http://visualstudiogallery.msdn.microsoft.com/c9eb3ba8-0c59-4944-9a62-6eee37294597

This file is available for Premium Users only.

any1 can reupload it?

@BFox

live link & other sexy tools here
http://forum.exetools.com/showthread.php?t=15292

Visual Assist of course, VTune for optimization, but also Image Watch. It's simply invaluable when working on anything related to image/video processing.

that reminds me what is the latest version of vtunes that supports vs2013?

Visual Assist
Visual Leak Detector

Visual Assist but even that can take up quite a lot of memory resources on a very large project.

ReSharper
my favorite!

Go To Definition is very usefull extention for visual studio
http://visualstudiogallery.msdn.microsoft.com/4b286b9c-4dd5-416b-b143-e31d36dc622b

resharper will support c++ too. when its out it will be awesome. EAP build were available afaik. more info here: http://blog.jetbrains.com/dotnet/2013/06/26/resharper-to-support-c/