Hi,

I'm using Subversion (just getting started). I have in the past used Visual SourceSafe. I found that to be nice and easy to use although I'm not sure how it would fair against your list of requirements.

Heres a couple of others you may want to consider...

http://www.devrace.com/en/athlant/ - Athlant
http://jedivcs.sourceforge.net/ - Jedi VCS

I've never used either of them so I can't comment.