I like & use very raspy mouth calls (to the offense of some on this board) - ie Woodhaven Red Wasp & Black Wasp... But, the raspy-est call I've ever put in my mouth is the Down and Dirty Anthrax mouth call; as I describe it, sounds like a "bar fightin' & chain-smokin' hen"!
A call I've been using a lot lately that's a good "balance" (gets real raspy when you push it real hard) is the Houndstooth Diamond X; I like it a lot...