MVC 3 Top 5 Reasons All new development should use it!
5. Once you Wrap you head around the Razor syntax you can really fly through an application
4. Entity Framework 4.1, using code first, builds the database for you!
3. You no longer have to listen to designers complain about the id attributes that .Net applies to the HTML
2. MVC3 with Razor plays nicely with the JQuery Libraries
1. Streamlines the development process and minimizes turn-around time.