Personally I love the Aussie one but that's a bit controversial. Jamaican must be the best around, can't see anyone dealing with the formidable Marley-Holding new ball partnership.
Contenders for the worst include Liverpool
and of course my own atrocious Northern Irish
dialect. Myself, Corrin and Furball tend to get on well because we all sound like lawnmowers being pushed across a pile of broken blackboards.