MacVim is a great complement to Vim for the Mac. One of the reasons why I started using MacVim was its built in support for the yank command to copy to the system's clipboard.
To get a copy of MacVim, you can grab the latest snapshot here.
When you download a snapshot of MacVim, you'll find a compressed file that includes MacVim.app, mvim (a command-line tool) and a README file.
One of the great things about using vim is that you can simply type vim filename.md
to open a file in vim from within the terminal. The mvim cli enables us to do the samething.