Life Eternal and Deus in Absentia are very good at closing off their respective album and their themes.
An album about death and the plague ends with a melanchonic ballad about mourning eternal loss, and an album about the rise of the antichrist paints a very bleak vision of the future. Spitalfields has really grown a lot on me, and although the lyrics are on point, it doesn't give me the "whoah, it's really the end, another empire has fallen" vibe. But the reprise of Imperium at the end is cool and does an Octavariumish "full circle" thing where it brings you back to the first line of Kaisarion, "we're building our empire from the ashes of the old".
And of course the chorus is very great: "We will break away together, I'll be shadow, you'll be the light... nothing ever lasts forever, we will go softly into the night"
And since we're talking about closers, Monster Clock is awesome as well!
I have a hard way to describe Infestissumam, but it's, dunno.... theatrical? cinematic? the first album was "just" retro doom metal, but the second one is more atmospheric, embellished with specific sounds and moods that really elevate many of the songs - the spooky waltz of Secular Haze, the retro style of Jigolo Har Megiddo, the atmosphere of the beginning of Zombie Queen, and of course Monstrance Clock is no exception. It's an album I could imagine being performed in a lavish theater, I know it's not everyone's favorite but I always found it very cool.
Actually it took me forever to get used to Meliora, that I basically bailed out during Papa III's era, I wish I was there for that. Only Prequelle "brought me back" and made me realize what I missed (I have seen Ghost opening for Maiden in 2013 when there was Papa II, and then I saw them open for Metallica with Cardinal Copia. Sad I missed Papa III!)