<p>Resharper, RefactorPro, etc?</p>

I have tried using Resharper for some while and also CodeRush with Refactor later on.
I have stayed with CodeRush/Refactor. There is one major difference - the discoverability of the commands. Their learning videos are quite nice and show you a lot.
Most importantly Coderush has one key/shortcut for all refactorings which makes you much more likely to actually use them. There is side window that shows you what keys to press in order to use the templates as well. I have liked Resharper's searching for usage of a method, but CodeRush has a similar feature ignited by Shift + F12 and you can also simply press Tab on a variable, function etc. to jump to its next usage.
I also liked the interface of CodeRush/Refactor more.
One of the pro's for Resharper is the integrated testing tool so yuo can run test directly from Visual Studio.