SmartGit is a Git client with support for GitHub Pull Requests+Comments, SVN and Mercurial. SmartGit/Hg will ask only when it needs a decision, but doesn't bother you with underlying technical constraints. Modify commits before pushing, commit individual lines within a file, resurrect lost commits and many more. No need to install and configure additional tools: SmartGit/Hg comes with a built-in SSH client, a File Compare and Merge tool.
Clone from GitHub, Assembla and other hosting providers. Create and resolve GitHub Pull Requests and Review Comments. See your repository state at one glance: your working tree, Git's Index, available branches, which commits need to be pushed.
SmartGit/Hg is free for non-commercial use and runs on Mac OS X, Windows and Linux.