Refer to this post for discussions on previous versions.
Asking the question again since Visual Studio 2010 has been officially released. Does anyone have any visibility this early on as to which is better? What about any other products that may be out there? This one will probably be on my dime, so I'd like the wisdom of those with experience before pulling the trigger on a decision.
IMHO I prefer CodeRush
The VS2010 version is out now ... Very stable,very performant.
Update: CodeRush also appears to be cheaper. R#r commercial license appears to be $349 where as CodeRush is $249 dropping to $99 on renewal
All that said, this is a very personal decision. It will depend very much on what you are after.
The following is a link to another answer I gave regarding things to consider when making the decision between tools like this.