VisualSVN Server - Get an easy to use Subversion (SVN) server for Windows. It works out-of-the-box and is suitable both for small business and enterprises. Available for free!
GitHub Desktop - GitHub Desktop is a seamless way to contribute to projects on GitHub and GitHub Enterprise.
uberSVN - Free, easy to implement UI for Subversion which includes:
Mercurial SCM - Mercurial is a free, distributed source control management tool.
VisualSVN - VisualSVN - Subversion plugin for Visual Studio
Git - Git is a free and open source version control system designed to handle everything from small to very large projects with speed and efficiency. It is easy to learn and lightweight with lighting fast performance that outclasses competitors.