Thanks everybody; I was looking at the names of every sort of passenger aircraft that came to mind, but thought I'd miss the most appropriate one.
To me, there's always been only three sizes of aircraft--small, such as a two-seater Piper Cub, medium-sized such as what might be described as "turbo-props" that make runs between medium-sized cities (20-50,000) in the Great Plains, and big, which is everything else.
I've of course flown on 727s and 747s, but seriously, when sitting inside an airport terminal, one's sense of size gets distorted. If placed side-by-side on a neutral field, I have no idea how a 747 would compare with a 707, for example.
I once saw in real life a deHavilland Comet, which was the very first passenger jet aircraft; I had no idea they made airplanes so massive during the late 1940s. That was a BIG flying machine, when one stood right by it. It was as big as a B-52, for all I knew (I've never in my life seen, first hand and up close, military aircraft, excepting those one- and two-seater prop jobs displayed in public parks the past 60 or so years).