Her accent in Sex and the City
I remember thinking way back when watching the first episode of Sex and the City , "if that girl is meant to be English, why does she sound exactly like an Australian?".
Virtually every syllable out of her mouth sounded Aussie. And I was thinking this before I even knew Sarah Wynter's nationality. I've seen some dreadful attempted accents on US TV in my time, but this has to be in the top 5.