Even though I think that VIM is the best text editor (please no Emacs vs VIM now) it is not a good editor for the casual user and doesn't blend into Mac OS X too well. Most of my coworkers in my old company didn't touch it with a ten foot pole - even though they were programmers. They used TextMate or Sublime or Coda. I tried to sell them on VIM but in the end the learning curve was too high and they settled for something where everything was easily reachable through menus.

So I think VIM is not a good example of a good free Mac text editor.

There's also Aquamacs for emacs fans.