Operations666
Educated Fool
Here's a thought I had that likely qualifies as a blasphemy on this particular forum: AMOLAD is basically the perfect sequel to TXF. Similarly dark thematically (both albums arguably largely deal in matters of life and death - war, religion, and existence in general), but better in every conceivable way and a more cohesive experience as a whole with no real dip points and a consistent quality of songwriting, all thanks to Bruce and Adrian being a part of the band. Of course Steve and Janick are far more on their game on this album as well if you ask me, but that's definitely more of a matter of opinion.
They are definitely the 2 most grim and depressing Maiden albums, in my opinion. Both to me feel gray and oppressive and are hard to listen to.