Surprised PeepOpen hasn't been mentioned yet. I use it exclusively with MacVim on OSX. It is a bit unconventional but works amazingly well: http://peepcode.com/products/peepopen
At this point, basically, if an editor doesn't support PeepOpen, I won't use that editor.
What's in your config for it?
In MacVim preferences, I set "Open files from applications" to "in the current window / and set the arglist"