Might be a cliched answer but I'm tempted to say Pink Floyd's Dark Side Of The Moon. All of the tracks are consistently great and wonderful to me!
When we are talking from an Objective standpoint I think it would have to be something that considerably influenced a lot of the music genre as a whole so .. hmm.. I'll have to think this one out
I'd have to say that would be the Hunky Dory album by David Bowie I feel it was extremely influential. OR maybe something to do with The Stooges, just certain bands that were huge influences.
(with my preferences aside i have my own opinions of "the greatest albums")
I.. uhm.. well.. if...
if I were to decide going by how influential, varied, and experimental an album is, I'd say the white album from The Beatles first and "Q: Are we not men? A: We are Devo!" second. That's just how I feel this very moment, though.
I would say perhaps Pink Floyd's The Wall, in terms of both good and influential
You're all overlooking the truly greatest album: Weird Al's "Mandatory Fun".
But for realsies, I'm not qualified to weigh in on an objectively best album. My tastes in music are arguably not good.