Nice freebie from Microsoft, Visual Web Developer 2008 Express Edition puts an (almost) fully featured .NET development environment at the fingertips of anybody who wants it.
So far I haven't found it lacking in any major way as far as ad-hoc .NET development goes, although J# is definitely missed. One feature I particularly like is the lightweight web server that fires up on a random port number to let you test out your ASP pages. No more having to copy test code over to a server every time you want to see how things are progressing.
Overall, an excellent choice for anybody that wants to get a toe in the .NET water, or those who only do a little bit of .NET work here and there, but for hardcore .NET developers it is unlikely to supplant Visual Studio any time soon.