Worst English:
1. England (Rumors in countries like Japan, wont hire native English speakers unless the speaker is or speaks the dialect commonly known as American. However, this is just a rumor for now)
2. New York/New England English
3. Southern United States
I personally enjoy the Canadian English. Reason I put England first, different word usage and how they pronounce certain words.
New England received my number two spot because I feel that people from New England, have a snobby accent which pisses me off.
Southern United States is third because it's only difficult to understand them when they start to slur their words together. Other than that, it's an OK sound.