I don't know if I'd say everyone should
own any albums, but maybe it would be fair to say that there are albums such that people could benefit from listening to them enough to form a somewhat informed opinion about them, even if it's that they hate them. I recently picked up My Bloody Valentine's
Loveless because from what I have read, it is just such an album. I was kind of hoping someone would mention it and validate me.

I would suggest
Kid A, even though I think a lot of its significance comes from the context of Radiohead's previous albums. I'd second
In The Aeroplane Over The Sea, too, though
On Avery Island seems less essential to my ears. There must be at least a couple Beatles albums, though I wouldn't count among them anything from before
Rubber Soul. Also I want to stick my neck out for The Cure's
Disintegration.