I really haven't experimented with anything but Git yet, and that's because:

• git-svn works really nicely, so it fairly easy to work in Git with $WORK's svn server.
• GitHub is brilliant. The UI is really nice and really helps explain Git's branching system of commits to people new to branching repositories.
• Having code I want to poke around with already up on GitHub is very convenient. Apart from Rakudo and perl6-examples, Test-More and Email-Sender are already there, and ripe for the branching.

My only complaint: unlike SVN, TortoiseGit isn't good enough for non-programmer usage just yet. The Windows Git GUI is much better, but with TortoiseSVN my non-programming workmates immediately understood how it worked. Git, with all its local/remote branching and whatnot, is a whole lot more complicated. Still, easy branching is an advantage hard to overlook, so I'll stick with Git and GitHub for now.