Personally I prefer bitter orange peel (called Curaco orange I believe) which is not the type you find in your grocery store, but is available at brewing supply stores. Naval and other sweet orange peels are seldom used.
A good example is Wit beer (a Belgian ale) which uses a mix of coriander and bitter orange peel at the end of the boil to add just a hint of spice to the finished beer. If you have never tried it, it is a great combination and one of my favorites.
Here's a Wit recipe I brew all the time with orange peel - it is a great beer:
http://beersmith.com/Recipes2/recipe_367.htm
Cheers!
Brad