A Matter of Life and Death is my favourite. It is in my personal top 5 of Maiden albums (right after The Number of the Beast, Seventh Son of a Seventh Son, Piece of Mind, and Powerslave) and is by far the most consistent of the reunion albums with great songs and a sound that suits the material perfectly. The Longest Day is one of my favourite Maiden songs of all time and rarely can the lyrics tell a story more vividly than here.
Second one would be The Book of Souls, with a right combination of outstanding epics (Empire of the Clouds, The Book of Souls) and short tracks that rock a lot (Speed of Light, Death or Glory). If Eternity Should Fail is a fantastic opening track, as also is The Great Unknown, which sounds like the A Matter of Life and Death top-notch material.
Third on the list would be Brave New World. The great stuff is amazing (the first four tracks could well be the strongest opening of a Maiden album ever ant The Thin Line Between Love and Hate is an amazing ending), but it also contains some fillers (The Mercenary, The Nomad).
Fourth on the list would be The Final Frontier. The second half, with its proggy material, is really great (Starblind and The Talisman being the tracks that stand out) and Coming Home is a fantastic and emotional song.
Last would be Dance of Death. It is probably the most uneven of the 5 albums in terms of quality, although it features one of the most amazing things Maiden has ever done (Paschendale). Montségur, Dance of Death, Rainmaker and Journeyman are top drawer material too, but things like Gates of Tomorrow, Wildest Dreams and, especially, Age of Innocence are quite mediocre.
To sum up, the albums range from the good to great, and to me are a significant improvement over their 90s output. I count myself lucky for having witnessed such a resurgence in the band.