I'm starting a new personal project on the side, so this is the first time I'll be able to start from the ground up on a larger project since ASP.NET 2.0 was first released. I'd like this to also be a good learning experience for me, so right now I'm planning on building this upon ASP.NET MVC, Castle ActiveRecord, and Ninject. I'm most comfortable with MbUnit for unit testing and CruiseControl for CI so right now they are the front runners.
But what would be your first additions once you click "New Solution"? Open Source, commercial, whatever. I have an open mind if they look like they can make it do what it do.