A few nice emacs ports in no particular order:
http://aquamacs.org/
http://www.porkrind.org/emacs/
http://homepage.mac.com/zenitani/emacs-e.html
There was a nice Xemacs port too, but there has been some kind of dispute over licensing so I'm not sure how actively it's maintained:
http://members.shaw.ca/akochoi-xemacs/Carbon XEmacs/Home.html
http://aquamacs.org/
http://www.porkrind.org/emacs/
http://homepage.mac.com/zenitani/emacs-e.html
There was a nice Xemacs port too, but there has been some kind of dispute over licensing so I'm not sure how actively it's maintained:
http://members.shaw.ca/akochoi-xemacs/Carbon XEmacs/Home.html