Joshua Feierman talks Mercurial:
While the choice of version control system is a very subjective and personal one, there are a number of reasons why I think Mercurial is an excellent choice, especially for someone just venturing into the world of version control. Here are a number of those reasons.
I prefer Mercurial to Git because I think the Mercurial commands are a bit easier to understand (although the proliferation of non-terrible Git GUIs has mitigated this somewhat). Nevertheless, if you love Git, use Git; if you love Mercurial, use Mercurial; if you love SVN, use SVN; if you love Visual Source Safe…use Mercurial or Git…