It depends on what you call "the best". PRR studied this question and determined that ACF cars were the best when looking at the factors they were considering. If longevity of the car body is your only consideration, then yes, Budd was probably the best. If you were considering passenger comfort, Pullman was generally quieter, and had better HVAC. If you consider wreck repair capability, Pullman was better as it was built of mild steel, followed by ACF. If you consider fuel economy, ACF and Budd were probably the best. If you look at design, ACF (arguably) had some great designs, as did Pullman.