A family relation of mine (via my wife) recently started blogging on all things .NET and had a runaway success with his list of fifteen (15!) Visual Studio addins.  Unlike other lists that you might see out there, Carl J actually took the time to install and try out each one so as to provide an informed and thoughtful opinion.

Fantastic work on this and I guarantee there's at least a couple there that even seasoned pros won't have heard of yet.  Check it out.