LifeCycle regularly uses FxCop to check our code for conformance to the Microsoft Patterns & Practices Design Guidelines.  This tool analyzes an assembly against rules governing good naming, security, and performance.  Where a problem is found, FxCop gives you a link to more MSDN guidance on the issue.  Not only a great quality assurance tool, but a good learning tool as well. 

But on the horizon are a crop of new code analysis tools that take the concept to the next level.  CodeIt.Right takes a similar approach- analyzing code and providing a list of violations.  However, CodeIt.Right also bakes in refactoring.  Not only does it tell you your Serializeable type should inherit ISerializable, but with one click, it will make the fix for you. 

NStatic analyzes code and reports on violations in an extremely readable graphical overlay displayed ontop of your code.  As far as I can tell, the violations it targets tend to be more subtle flaws in logic within procedures.

Neither is ready for prime time- CodeIt.Right is in beta and was a little buggy in my testing and NStatic isn't available to the public at all yet.  Still, if your interested in writing quality code, these are two products to keep bookmarked.