As an .NET application developer, the following 9 websites are my most frequently visited websites.
I learned .NET and get a lot of resources from this website.
MSDN's primary web presence at msdn.microsoft.com is a collection of sites for the developer community that provide information, documentation, and discussion which is authored both by Microsoft and by the community at large. Recent emphasis on and incorporation of applications such as forums, blogs, library annotations, and social bookmarking are changing the nature of the MSDN site from a one-way information service to an open dialog between Microsoft and the developer community.
I downloaded many source code from this website. There are also many very good articles.
8. Chanel 9
Many videos introducing very cool and latest Microsoft technologies.
9. ScottGu's Glog
The About Me Page of this blog:
My name is Scott Guthrie, and I am a Corporate Vice President in the Microsoft Developer Division. I run the development teams that build the following products/technologies:
* CLR and the core .NET Base Class Libraries
* IIS 7.0
* Visual Studio Tools for ASP.NET, WPF, Silverlight and Mobile