Aurees - A Git client for Windows, Mac and Linux.
GitKraken - The intuitive, fast, and beautiful cross-platform Git client.
gitg - gitg is a git repository viewer targeting gtk+/GNOME.
SmartGit - SmartGit is a front-end for the distributed version control system Git and runs on Windows, Mac OS...
Qgit - Qgit is one of the smart tools that implement a GUIO for the most common SIGT commands like pop, push, shave and apply matches, making the developer browse revision tree, view patch content, or change files.
SourceTree - Mac and Windows client for Mercurial and Git.