At $work we use CVS (but may shift to SVN). At home for developing small Perl based projects I use Subversion. In both places I use Windows and either TortoiseCVS or TortoiseSVN. Tortoise takes a lot of the pain out of using either product.

I did experiment with RCS and CVS in my early Linux days, but having used SVN for some time and being aware that it is at all effects intended to be a replacement for CVS addressing its flaws, I wouldn't go the CVS route in any case. Unless I had to, that is. But talking about something I need for personal use, I certainly don't "have to" adopt anything particular.

I saw the documentation for TortoiseSVN and although it seems definitely cool, and useful, and having it installed under Windows would most certainly not do any harm, I'm more of a cli kinda guy, and I wouldn't rate high in my requirements the availability of gui tools.

One of my reasons for using a RCS at home is because I work on a couple of machines (laptop and desktop).

That's exactly the same situation as mine, except that I may want to have my utilities available on some other systems too, that are not strictly @ $home, and I may want to update them there too, easily propagating the updates to other locations, of course.

I had a brief look at Monotone, but without a client I didn't persist with it.

In which sense? I had a brief look at its homepage too, as hinted in the root node. Indeed it seems that it doesn't follow a C/S architecture, but rather a distributed one. Yet AIUI there are versions of the program available for most common architectures...

Update: I should add that there are some important differences between CVS and SVN. Most important is that CVS deals with files - it has no idea of the relationships between files nor any way of tracking files if they move, are refactored or change their names. SVN on the other hand deals with the whole repository - a commit is an update of the state of the whole repository and thus tracks directory structure and file name and location related changes.

Indeed, that's a big plus for me. In fact, even if my stuff is small in size I may still have some script splitting in two, or becoming something different from what it was initially thought to be and changing name accordingly. Or spawining a module. And I would like to keep track of these changes. Of course this a feature that AFAICT all modern SCMs have...