What is the best version control solution when working with ASP.NET, where the criteria are ease of implementation, low cost, and ease of use?

+1 for Git. VS2013 works well with Git/Github and VS2012 with SP1 and extension does too. There are still some issues (e.g. branch switching can throw an error from the extension) but working through a bash window as most Git users will, there's nothing serious to concern. I've used TFS (now Visual Studio Online) and much prefer Git.

We have been using TFS for years, without doubt it is best with visual studio. But licenses are very expensive and we wanted to involve more people to do task management along with version control. TFS is very expensive as each user needs to have TFS CAL. We recently migrated to Github with GitHub for Window client. It is really good. For private repository, it costs $7 per month for upto 5 repositories with unlimited users. Visual Stufio 2013 also has git integration. The only drawback git has is you have to do two steps, first commit and then sync changes to remote repository.