I would say that the final choice depends on the needs. For centralized repositories (cvs, svn etc.) you will need a pc that will act as a server for the repositories. Everything has to be commited to the central repository. I like decentralized repository models better (bazaar, mercurial, darcs). You get all the benefits of the centralized repos plus the fact that each checkout is a full repository on each own. Branching and merging is a piece of cake.
If you need a centralized repo then go with svn.
If you don't I suggest darcs.

At work we still use cvs (it's the most mature source control system).
At home/fun I am using darcs (imagine that my "repository" lives on a usb stick).

P.S. After you are finished selecting a source control solution you should also start serching around for a good bug tracker