Mercurial is the best balance of simplicity and provides a modern source-control tool.
You can use TortoiseHg which is very similar to TortoiseSvn so you'll have a low learning curve there.
git is a bit more powerful than Mercurial and it's a bit more complicated to use but they have very similar core features.
I don't see much reason to use any version control tool other than mercurial or git. If you have a shared/map Windows drive then you have what you need to get started.
Git or Mercurial. Both are extremely identical, both have awesome UI's, both have great command line.
Canonicals Bazaar gets my next vote
As a person who works on Web and Software on Linux, Mac, and Windows, GIT has been my go-to everywhere.
I use git with SourceTree for my personal projects. It makes source control really painless. Using git with command line is not that bad either though there is a slightly higher learning curve for it.
I used SVN a lot (even home repositories for all kind of stuff) and was one of those "don't fix it if it isn't broken" guys towards version control, looking sceptically at this git-"hype". However one day I had to learn/use git because work demanded it. It easily outperforms SVN in every way and made all sourcecode managing a piece of cake. So if you're a die-hard SVN user you might consider trying git for your next project. (don't know about mercurial though, heard it's similar to git)
