Hands down CD Sr, followed by REO. I've experienced their fundamentals first hand in multiple games, including the one I'm actually good at. Based on me as a viewer, DJT is up there. And as much as we may not get along, based on playing him in MK9 and INJ, Pig's fundamentals are on point.
That said, I think we should revisit this again this time next year. MKX might bring out the best in everyone, maybe even completely new names. I also wouldn't mind a "best footsies" thread. Footsies are the best part of fighters in my OPinion.