Dick Van Dyke – Mary Poppins (1964)

American actor Dick Van Dyke has dubbed his attempted accent in this film “the most atrocious cockney accent in the history of cinema.” Yikes… but we won’t disagree; it was pretty bad. We also now know for sure that Van Dyke will be making an appearance in the new Mary Poppins film starring Emily Blunt – let’s hope he’s learned his lesson and retired the accent for good.