It's cool that VS has intellisense for C# (the feature where in the middle of typing an expression, a little window pops up listing possible things to complete the expression), and that it seems to be very consistently accurate.
I've noticed that it just always seems to do the right thing. It's like it's reading my mind. Things that I've personally noticed and appreciated as a developer:
Overall, it just seems to be very well integrated with a lot of different language features and to consistently do what I'd expect it to.
(I'm sure VB is great too; but since I don't really use VB, I can't comment on my personal experience as a VB developer)