C# ASP.NET MVC with Web API
Why?: C# is a powerful programming language and it has Linq which simplifies everything.
It also has:
-Attributes which allow you to do a lot of things Including the ability to tell the user what they can see (what they have access to), Roles to have admins etc
-Entity Framework Code First: basically your database is generated from your data Model so you can easily change your database in code.
-Easy deployment with Azure
-SQL injection isn't a problem
-Web Configs allow you to cleanly set up connections to Web services, databases and security protocols and you can easily change environment (Development, Testing, Live)
-Fully understand the meaning of MVC and MVVM
-Visual Studio by Microsoft
-NUNIT and Moq for unit testing.
-Nuget Packet Manager
-You can easily add external libraries and frameworks like KnockoutJS and AngularJS (I think).
Although it is a lot at first once you get used to it you can do so much.
Feel free to correct me.