That seven year period from '73 - '79 saw Dark Side, Wish You Were Here, Animals, and The Wall. As a collection of four successive albums, this group of discs is unparalleled except by arguably Led Zeppelin or the Beatles over the course of the '70s ... well, hard core Jethro Tull fans might be the exception to the general public.
But it seems to me that every die hard Floyd fan that I know, those who own everything ever released by the group, will never name the usual suspects. For the most part, everyone I know who is off the deep end when it comes to Floyd will always name either Atom Heart or Animals, which is essentially the least known of the four discs that came out during that period between the mid/late '70s.