Git vs. Mercurial
Excellent discussion of Git’s benefits by Aristotle Pagaltzis. One killer feature I didn’t know about:
Lastly, the thing that really swayed me is git-svn. This is an integration tool that lets you check out from and push back to a Subversion repository, while working in a git repository on your own machine. The integration with Subversion is incredibly slick. This means you can use git rather than SVK (which is a castle built on sand) to get your DVCSy goodness when working on a project that uses Subversion.