I'm gona vote for Tiffany Mynx, especially in the last few years. I've seen her swallow cum, get DP'ed, pised on, and pis on people, She's really nasty!
I am going to say the Long sisters, Ashley Long and Angel Long, they both talk dirty, fuck dirty(repetitive gang bangs), always doing double anals, D.P, and other things, i would have to say their dirty and they have that hot british accent!