Visual Studio 2010 at home and 2008 at work. We're primarily .NET so the two just kind of go hand in hand. I'm also spoiled by intellisense.
I also use Eclipse at work since we've been doing a lot with GWT on the client side (thought still using .NET on the backend).
Finally, I'll often use notepad++ for anything JavaScript simply because it takes far too long to load up VS when I want to do something small/edit a file/etc.