There's no way I could come up with an answer to this. There's too many. Other than the Stones and Beatles, Hendrix (see what I mean?), etc, the first image that came to my mind was Marvin Gaye's What's Going On album. But there's just a million really obvious and not so obvious ones you could make a case for.

Actually, I don't think that favorite necessarily equates to best... I can think of a few examples where an artist has a superior release but it wouldn't be the one from their catalogue that I would take with me to a desert island.

I thought it would be fun to wait until the weekend and have a "playoff" this morning with the ones that, to me at least, might stake a claim to this title: Pet Sounds, Who's Next, Aja, Sgt. Pepper's, Tommy, Rumours, Silk Degrees and The Lexicon of Love. After listening to them in this order and comparing pros and cons, I couldn't vote for any of the other seven over Sgt. Pepper.

This is a great way to spend a cold Saturday morning.

That's a good way to do it.
Whenever the subject of best or favorite album comes up, I always mention "Layla...".Usually, a short time after, I play the album, just to make sure nothing has changed. So far, after 35 years or so, it's still the 1 for me.
"London Calling" and "Abbey Road" come awfully close.One day, if Clapton pisses me off enough, either one may overtake "Layla...".I bet that would teach him a lesson, I bet.

My opinion could be completely different a week from now than it is today.