First of all, I don't find French sexy. At all.
My favorite Accent [of English] is Spanish. Like, Antonio Banderas kind of accent. That kind of accent is so attractive. <3
That's one reason why I really like Zevron from Dragon Age: Origins.
Though, I do not like the Spanish language. I think is sounds better as an accent of English.
Now, I do not find the Japanese accent [Of English] to be attractive at all...
HOWEVER, I think that the really -deep-voiced Japanese voices are really attractive when they are speaking Japanese.
I also like Russian accents. Both in English, and Russian. But I like them with deep voices.
(I also like Nigerian, Swedish, Romanian, and probably a few others that I don't know the name of...)