What's the best or worst accent you have heard in a movie?

I am currently watching 'The Departed' and the accents are all over the place. I get that the Boston accent is sometimes overdone in TV and movies but some of the accents are truly terrible in this movie (Ray Winstone barely covers his Cockney accent). But the accent that is most jarring is Matt Damon's, he is from Boston, and his accent was natural in 'Good Will Hunting', so why does it sound so put-on in this movie? It is by no means the worst in this movie but it sounds false next to Mark Wahlberg. (I am not from Boston though so maybe it sounds fine to a Boston native).Are there any movies where an accent really annoys you or where you feel an actor does a really good job with an accent? via /r/movies https://ift.tt/2EYBRpo