I would have to say Nancy Barrett had the best scream out of the women. Who could forget that loud long & terrifying scream she let out while playing the character of Millicent Collins as she's being bitten by Barnabas up in the tower room.
That's my favorite scream!! They use it on all like DS-promo type commercials and stuff, too. Or pictures about Barnabus being a vampire .... they use him biting Millicent ... I always thought she was some "dock girl" that he was biting, and then I saw the episode, and I was like "OMG That's Millicent!!" BWAHAHA that's so kewl! NB has such a loud, long scream!! She gets my vote, too ^_^