I think there is a difference between a "band's catalogue" and "general culture".
I don't think it's a rule, but I am a proponent of the idea that you generally like the albums that got you into a band more than those that came before or after, because by definition "Artists change" and if you're not changing with them (getting older, getting married, getting pregnant) you stand the risk of "losing" them. I know for me, I got into DT in '92 with Images and Words and while I love the run up through Octavarium, I&W is still the gold standard. I got into Kiss with Kiss Alive II, and so the first six are and will always be, iconic. I got into Genesis with Abacab and the "In Concert" film, and so the golden age for me is The Lamb through Three Sides Live.
As for "general culture", it's different. I was there when Appetite was released, and it was legend from day one. Thriller too. You knew this was not like what came before. Born In The USA was a landmark record from Day One, and even non-fans (like me) knew it. But there are sleepers; Pyromania and Hysteria were both slow burners. Hell, Lep was an opening act on the first leg of the Pyromania tour. I saw the first leg of the Joshua Tree tour, and while that is less of a classic album than the album hat broke the band, it's still fun to watch.
There's also the element of "album" versus "movement". I firmly believe that in ten more years, Nirvana will be far more well known for the fate of their singer, and the idea of their genre than for the album itself.
I think there will always be an element of "past" in order to put things in perspective. I think we can love the new Steven Wilson album to bits, but the reality is, it's not a classic album and won't be unless and until it breaks out of the genre and survives the scrutiny of a decade or two.