I doubt it, that any other editor resp. IDE software is able to hold a candle to GNU emacs with its plugged in version control access to subversion, RCS, and CVS.
Once again I can just shout out to the world: I love emacs.
Where would my productivity be without emacs?
I almost never need to use my mouse to do anything within emacs.
(Alright, once in a while I use the emacs GUI menu to remind me of the appropriate shortcut …)
My hands can keep, where they can achieve the most: on the keyboard.
Update 2013-01-07:
This article attracted far too much SPAM, so I had to disable commenting.