SvnBridge
I love this tool from the CodePlex guys! I mentioned a while ago that I was having some issues with the various TFS clients available and this one seems to of come up trumps! Admittedly there is no feature to close work item's with a check-in, nor add/edit them but that aside this is really something!
A long time ago I used Subversion and TortoiseSvn a lot and then suddenly started using TFS related clients because of the server technology.
The only thing I would raise is that the actions seem to be quite slow when transferring small files to the TFS server, however when transferring large files the transfer rate seems to increase exponentially after a few seconds - this is not the case with their smaller counterparts.
So far I have not looked back since moving to the said tools.