Visual Studio contains more than just an IDE/compiler for Visual Basic, but also C++, C#, Web environment, also more project types for each of them then normal edition for each of them i believe.
I have Visual Studio because I plan on future development in languages other than VB.
Really it matters, if you plan on only doing VB development, get the Express one, but if you want different languages, then get Visual Studio.
As, brinuz and lolland said, it contains a complete .Net languages suite.
But it has some great features for .NET professionals including full support for LINQ and Windows Presentation Foundation (WPF).