Pretty much any accent, really. An exotic manner of speech instantly adds +5 to Sexterity.
Of course, being the Anglophile I am... most accents from that damp little island off the coast of France are pretty hot. Scottish in particular (I'm looking at you, actress-who-plays-Amy Pond).
And yes, I know that "Anglophile" technically only applies to the English. I just don't want to say "Britophile", because I think it sounds weird.