Probably been done before on here, but hey, whatever.
Exactly what it says in the title. Can an album be truly great with one terrible song? Maybe. For the sake of this thread, yes.
I’ll say Father John Misty - I Love you, Honeybear with the song True Affection.
Incongruously bad compared to the rest of the album, which is fucking great. Have to skip past and pretend it doesn’t exist every time.