[tom9729]

Gitg (https://wiki.gnome.org/Apps/Gitg/) looks decent, although it's Linux-only. It's like git-gui and gitk merged into a GTK3 interface.

It would be cool if Atlassian would open-source their client (SourceTree). They make money off of Bitbucket/Stash and provide SourceTree as freeware, so it seems like a no-brainer to open-source it and let the community port it to Linux.