I think we might be missing the point here a bit. Comfort in an airplane may have something to do with the type/model, but mostly is dependent on the configuration. If you have sat in some of the Asian Airlines' 777, I suspect you will take the old 737 set-up in most US domestic airlines anytime. On the other hand, EVA's Evergreen Delexe Class (an Advance Coach arrangement) is better than most US domestic FirstClasses and you can find that in their DC-10s, 767s, and 747s. As to "AIRPLANE" per se, I think 757s are the worse. They recirculate more air than any other models and give you higher probabilities of catching all the strange germs your fellow passengers are carrying. And the seats set-up usually are not as spacious than the old 737s or 727s. Or, may be we are all just becoming wider in bodies than the old days.