ASP.NET MVC is Microsoft's implementation of the MVC pattern for ASP.NET.
WiX is the Windows Installer toolkit, a power way of creating installers.
Newly included in .Net 4.0, a look at Code Contracts and static analysis.
A look at the Parallel class, .Net 4.0's new functionality to simplify multi-threading.
A replacement to Reflector, ILSpy is a powerful decompiler.