I was trying to figure out which unit testing framework to adopt on a project I’m involved with. My hunch was definitely NUnit & MbUnit ( where appropriate ), but a couple of dudes in the project pulled an impressive comparison table that almost had me convinced on choosing Visual Studio Team Test. Then I stumbled upon the following post by Roy Osherove ( bow down ) which made me realize that Visual Studio Team Test is probably not the way to go any time soon. Make sure you read the discussion following the post.

The main issues that pissed me off are:

• Bugs - Sure, NUnit has bugs as well, but at least its open-source and frequently released.
• Coupling to Visual Studio - No standalone UI.
• Inheritance Not Supported - The showstopper. If you can’t inherit, your are prone to sloppy design which will eventually lead you to code duplication and/or poor coverage. see http://vaultofthoughts.net/TestMethodInTheAbstractClass.aspx.

http://weblogs.asp.net/rosherove/archive/2006/09/24/MbUnit-vs.-NUnit-Vs.-Team-System-Unit-Testing-_2D00_-Choosing-a-unit-test-framework.aspx

Unless you are applying design techniques to your unit tests, they can become quite messy. In such cases, being familiar with these anti-patterns can help you stay away from trouble.

http://blog.james-carr.org/?p=44

An excellent beginner’s article.
I recommend this to everyone I teach TDD.

http://www.methodsandtools.com/archive/archive.php?id=20