My personal favorites are Jeanna Fine and Heather Brooke (AKA Heather Harmon). They almost make it look effortless taking cocks all the way down. Never sounding like they are about to gag up their lunch. Couple of great cocksuckers.
Though, Bobbi Starr is clearly the hands down favorite. If you haven't haven't seen it, there is a .gif on the internet. She's taken the dick and the balls into her mouth in one full swoop.