I use Resharper from Jetbrains... starting up VS is a little slower, however the refactorings are super speedy - does a great job caching and giving u edit time compilation checking.

we tried Ankh and it's garbage. It doesn't use the built-in version control API for VS 2005, so half the time it doesn't do what u want. besides, the look and feel is rather nasty, compared to the clean UI of the rest of the IDE. We now use Tortoise Plug-in for Explorer and it works great. It's really not that big of a deal to switch to the explorer window and commit ur changes. There are better plug-ins that integrate with VS 2005, however they are not free :(

We started out with Visual Source Safe and after about 1 month we ditched it in favor of Subversion and haven't looked back since. Subversion is vastly superior to VSS and CVS and I would argue THE best open source version control system.