Here I am belatedly with some answers to my own questions:
First, as I explained to Mr. Covil, I wasn’t necessarily asking whether the albums I cited were the bands’ best in their own histories. I was merely pitting some of their signature albums (some with themes throughout, like the two Who albums) against each other. For example, many would place “Who’s Next” at the top of the band’s catalog. Sorry I didn’t make that clear at the beginning.
As for The Who, I choose “Quadrophenia” by a hair over “Tommy.” What places the rock opera slightly behind for me is the overlong “Underture” that ended the first of the two-album set (on vinyl). “Quadrophenia” also has some extended instrumentals, but not one millisecond of that double album is unlistenable to me. Side note on these two musical masterpieces: I got to see (from the second row) the play “Tommy” performed at the Universal Amphitheatre in Los Angeles many years ago, and also saw what was left of The Who (John Entwistle was still alive) perform “Quadrophenia” in its entirety at Walnut Creek a few years ago. Both were outstanding, and if you get a chance to see a good production of “Tommy,” don’t miss it. Much different experience from the album, concert or movie.
Another Who side note: While I really like the song, Jenna, I remember in high school when “Face Dances” was released, “You Better You Bet” was mocked by all my friends as pop and that the Who had sidetracked from serious rock into commercial fluff. I disagreed.
Others: “Abbey Road” over “Sgt. Peppers,” only because I can do without “Within You Without You.” “I Want You” from Abbey Road is overlong, but I think that was the point of that song.
“Physical Graffiti” is my favorite Zeppelin album, maybe because none of the great songs on it have been overplayed on classic rock stations (which I don’t listen to anymore anyway).
Hard to choose between the Floyd albums, but “Dark Side of the Moon” was just so groundbreaking. Wow.
And I really didn’t grow up as knowledgeable about the Stones albums, which probably showed in my initial question. But I still liked everything of theirs I knew. “Wild Horses,” “Can’t You Hear Me Knocking,” and “Dead Flowers” probably put “Sticky Fingers” at the top for me. Shame on me for not putting “Exile on Main Street” as an option.