a Hawthorn bush is in my opinion the best ,looks good when clipped and prevents outsiders with a lovely display of berries.no contest.
Hawthorn is a great hedging plant. There are also some arguments to be said for mixing blackthorn with it. The hedge is then more diverse. The blackthorn will flower earlier, and makes a pretty sight (as does hawthorn, a bit later). Provided that you allow the hedge to flower, and don't trim all the buds off.
A very best way to control hawthorn is by laying it. My neighbour does this. That actually makes the hedge stronger, as you have major branches forming a horizontal barrier. He also has some holly (slow growing, but evergreen) in his hedge too.
I suppose the choice really depends on your personal taste and whether that veers towards tidiness, in which case you'd prefer the hedge to appear uniform; or whether wildlife considerations are uppermost, and you don't mind a mix.