My favorite is my wife's trick learned from her Brownie days: slice an apple in half, spoon out both cores, put squeeze margarine in one half, brown sugar in the other, put the halves together, wrap in foil and roast in the coals.  These are great because you can save them for late night after the food bag's up.  To kick it up a notch (thanks Emeril): warm up a little brandy and flambé the apple right before eating. Oh baby.