We use git + ucpp on linux. I'm working on getting a nicer makefile generator that handles dependencies better and a native (not through wine) compiler for next year. So far, git has worked extremely well. Github is also awesome - probably the biggest plus for git.
I haven't use hg though, so I can't comment on which is better.
Why would you be checking in a big movie? You have to git add it explicitly before it will be tracked, even if you always just git commit -a. Unless you're doing git add * - but in that case, maybe you deserve the extra work
At least do git add *.h *.cpp if you're lazy.