I would go with mercurial. It just works well with both Windows and Linux (I don't have a MAC). And like alfred said, hoping is not a good option for you. I would always go with any tool, that's proven that obscure. Playing around with it, and testing it is fine if you are a <4 people team. Anything more than 4, and I think it's time to google "XYZ number of users" and it will show you stuff.

If you still need more information to be sure, I think I trust these two, esp recommend the google code link.

http://code.google.com/p/support/wiki/DVCSAnalysis

http://rg03.wordpress.com/2009/04/07/mercurial-vs-git/ This one is a little balanced. more like a good info on internals of both. A little too long, and I didn't like the fact that the guy says both are great, in summary. I knew that already...pick a side if u write a VS article...or else what's the point.....