As much as I love 17 Seconds by The Cure, if you took away 'A Forest' it would lose some of its appeal. Disintegration saw Fatboy Smith at his peak of self loathing, yet he still managed to slip in some commercially successful tracks (Lovesong, Lullaby) into a doomfest of magnificent proportions.
Absolute bitch to choose which album, but I have gone for Low Life. There are still the scars of JD in it, combined with the movement towards dance in the form of Subculture and The Perfect Kiss. They were never JUST a singles band, although their singles were peerless for a time.