I\'ve been programming for 10+ years now for the same employer and only source code control we\'ve ever used is VSS. (Sorry - That\'s what they had when I started). There\'s
I'd say stick with what works for you. Unless you are having issues with VSS, why switch? Subversion is swell, though a little sticky to begin using it. TFS is far better than VSS, though it is fairly expensive for such a small team. I have not used git so I can't really speak to it.
I'd probably go with Subversion, if I were you. I'm a total Git fanatic at this point, but Subversion certainly has some advantages:
Git has many, many other advantages, but the above tend to be the ones people care about when asking general questions like the above.
Edit: the company I now work for is using VisualSVN server, which is free. It makes setting up a Subversion repository on a Windows server stupid simple, and on the client we're using TortoiseSVN (for shell integration) and AnkhSVN for Visual Studio support. It's quite good, and should be fairly easy for even VSS users to pick up.
Latter-day Edit: So....nearly eight years later, I would never recommend Subversion to anyone for any reason. I don't really recant, per se, because I think my advice was valid at the time. However, in 2016, Subversion retains almost none of the advantages it used to have over Git. The tooling for Git is superior to (and much more diverse) what it once was, and in particular, there's GitHub and other good Git hosting providers (BitBucket, Beanstalk, Visual Studio Online, just off the top of my head). Visual Studio now has Git support out-of-the-box, and it's actually pretty good. There are even PowerShell modules to give a more native Windows experience to denizens of the console. Git is even easier to set up and use than Subversion and doesn't require a server component. Git has become as ubiquitous as any single tool can be, and you really would only be cheating yourself to not use it (unless you just really want to use something not-Git). Don't misunderstand - this isn't me hating on Subversion, but rather me recognizing that it's a tool from another time, rather like a straight razor for shaving.
Whatever you do, don't change for the sake of changing.
If it's working for you and you're not having problems with it, I don't see any reason to switch.
VSS is horrible. I may be channelling Spolsky (not sure if he's said this), but using VSS is actually worse than not using source control at all. Despite its name, it isn't safe. It creates the illusion of safety without providing it.
Without VSS, you'd probably be making regular backups of your code. With VSS, you'll think, "Mehh, it's already under source control. Why bother backing up?" Great until it corrupts your entire codebase and you lose everything. (This, incidentally, happened at a company I worked at.)
Get rid of VSS as soon as you can and switch to a real source control solution.
At work we use subversion with TortoiseSVN - works very nicely but it is philosophically different to VSS (not really a problem if there's just you but worth being aware of). I really like the fact that the whole repository has a revision number.
Given a free choice I'd've probably gone with vault but at the time I had zero budget.
I'm looking at things for personal use. There are reasons to use subversion and reasons to use something completely different. The alternatives I'm considering are Vault (as before, free for single use) and Bazaar. GIT I've had to dismiss as I am, unashamedly, a Windows person and right now GIT just isn't.
The distributed nature of GIT and the option of private/temporary checkins (assuming I've understood what I've read) is attractive - hence my looking at Bazaar.
Update: I did some more digging and playing and I actually went for Mercurial for personal use, integrated install with TortoiseHg makes things very simple and it seems to be well regarded. I'm still trying to work out how to force an automagic mirror of commits to a server and there appear to be some minor limitations to the ignore function but its doing the job nicely so far...
Murph
I've recently started using Mercurial for some of my work. It's a distributed system like Git but seems easier to use and seems far better supported on Windows, the latter of which was crucial for me.
With distributed source code control every user has a complete local copy of the repository. If you're the only person working on a project, as you say you often are, this can simplify things a lot since you just create your own repository and do all your commits etc. locally. If you want to bring on other developers later you can just push the full contents of your repository - current versions and all history - to another system, either on a shared server or directly on to another users' workstation.
If you're working only with a local repository remember you'll need a also backup solution as there isn't a copy of all your code on a shared server.
I think that Mercurial has lots of other advantages over Subversion, but it does have a big downside which has already been mentioned as a plus point of Subversion: there a lots of third party tools and integrations for Subversion. As Mercurial hasn't been around nearly as ong the choice is much less. On Windows it seems that you either have to use the command line (my choice) or the TortoiseHg Windows Explorer integration.