I'm a big fan of the Visual Studio Express 2005 range of products. They cost nothing and are pretty powerful. In some respects they're better than the full-blown version of Visual Studio. They are super quick to load and if you're using FTP to upload ASP.NET web sites, Web Developer is easier to use than Visual Studio. I've been using it for the FreeFlow web site for a while. So I took the plunge and downloaded the beta 2 of the 2008 version of the C# and Web Developer.
First impressions are good. The install was flawless. C# comes with a WPF designer, so I can finally get down to learning that without having to hand-code it. The Web Developer version comes with some AJAX controls so I can play around with them as well. And it's still free.
The question is will there come a time when all Microsoft's development tools are free? We're signed up for the Empower program so they are virtually free for us anyway and presumably lots of other companies are on the same or similar programs. So my guess is Microsoft aren't actually making any money on development tools and with the free tools now being pretty damn good, I'm pretty sure they'll give the full versions away some time soon just to keep us all hooked.