SourceTree - Mac and Windows client for Mercurial and Git.
TortoiseSVN - The coolest interface to (Sub)version control
GitKraken - The intuitive, fast, and beautiful cross-platform Git client.
SnailSVN - Similar to Tortoise SVN for Windows but integrated into Finder
GitLab - Create, review and deploy code together with GitLab open source git repo management software | GitLab
Xversion - Super easy enterprise class version control.