Ah, silly Maiden thread time! But you sold it so nicely, I'm in!
Mind you, some things I'll say should not be taken seriously. Don't know which yet. Let's go! (chronologically)
Killers (1981)
When people describe the debut album with "raw" or "rough" I don't know if they mean production or the songs themselves. Apart from title track and Prowler, I wouldn't say the rest of them are rough. Not even aggressive. Killers on the other hand (apart from Prodigal Son) oozes with that aggressiveness and speed that was noticeable on some tracks on the debut album. But unlike "Iron Maiden", which is all over the place (as is usually with most debut albums since band or artist took a long time to make them) Maiden passed "curse of the second album" with a thumb up by one man solely, and it's a great indicator about the future of the band. More than 40 years later (!!!), that same guy takes more than 50% of the album (of which 25% are awesome). Also, Paul diAnno. To me, vocal plays a big part in music, and it wouldn't be fair to exclude him (or Blaze) if I'm making Maiden palette.
Powerslave (1985)
All you Charlotte-fu**ers calling this one Fillerslave forget what's not "filler" on this album (side note: not a filler to me - I'd take those four middle tracks over majority of 90s Maiden). Anthemic opener, radio hit single, progressive masterpiece (progressive because progresses from great to "OMFG") and an epic which is constantly considered as one of their best. Yes, there is no gallop here and previous two albums also had their hit singles. But NOTB fired is some directions that weren't attempted again or recreated, and POM just keeps dipping in quality as the albums goes, reaching some run-of-the-mill tunes. Furthermore, maybe the next two albums deserve this spot, but then again - SIT has synth, but the formula is still the same as on the previous three. 7th Son maybe has this more focused approach and is definitely a step-up in terms of grandeur, but again, it's more similar to Powerslave than to anything that happened after. And Powerslave came first, so there you go. Earl bird gets the worm.
Fear of the Dark (1992)
Dare I say cock-rock? No. But when you simplify things and move on to topics like money, motorbikes and hooligans - you may not stand out from the rest of the scene, but you're going to stand out from the rest of your discography. Not like that's a bad thing. Venturing into Maiden, I got hooked on some of these tunes, while some later 80s stuff didn't sit well at first (the verdict is opposite now). I dare saying this is maybe the most commercial album of theirs, making it also most approachable, I guess? Also, it has signs of doom and gloom that are going to play a heavy factor in 90s and in some cases in reunion era.
Virtual XI (1998)
I wrote what I wrote - Virtual XI. I said I'm going to include Blaze, so I did. The previous Blaze album kind of merges with FOTD in some aspects, so there's nothing new there. On the other hand, welcome to an era of long choruses, long intros and whoo-hoa sing-a-long parts. And Steve questioning everything around him. Also, it's better when a palette has more color, right? What's more colorful than sticking The Angel and the Gambler with Wratchild, Ancient Mariner and Fugitive?!
Senjutsu (2021)
Brave New World is my favorite album. It's definitely the "new" Maiden. But if I include it here, Senjutsu would be out and Senjutsu has more to offer. Taking anything you want from reunion era - Senjutsu has it. Hell, take everything from their discography - Senjutsu has it. Aggressiveness, goofiness, prog-influenced elements, ballads, epics, short rockers, anything really that Maiden had done - it's here (and in some cases it's taken to a whole another level). Hell, just skim around threads when Senjutsu came out, there'll be term "self-plagiarism" on every page.
Brave New World was really something new, something different. Some say it's a continuation of VXI (and not just because Dream of Mirrors was made during those sessions) and I see what they point at. But since then, every album has been a step further in that direction (AMOLAD being an exception, but more on that later). I've read once that BNW played it safe while on Dance of Death band fired on all guns, and I somewhat agree with that (although some of those were blanks). You couldn't find Paschendale on BNW or any previous albums, same as you couldn't find Starblind on Dance of Death (I still think The Final Frontier is a great continuation on Dance of Death in terms of upping their game in certain areas). AMOLAD is something different (and no way I'm saying it's a conceptual album. The best you can get from me is 'coherent'). But that doomy/depressive atmosphere was done before, those prog and epic elements were done after so, to me, AMOLAD really isn't presentable as 'different color' in a pallet. After all, AMOLAD only uses those army colors, not much to draw with there.
Reviews for Senjutsu were mostly positive (except those couple of individuals who got extremely disappointed with Senjutsu, and wrote it's their worst and some other fairy tales) and there is a reason for that. No matter, what your favorite Maiden song, album, era is - there has to be a riff, lead melody, lyric line, drum fill take reminded you why you love listening to Iron Maiden (please, no Legacy/Talisman/Time Machine jokes here - if you rehash your jokes about Janick rehashing his parts then he's the kettle, and you're smoking pot. Or Janick called you pot. Or you're kettle. Something like that.) Anyway, nothing to do with topic anymore, but Senjutsu rocks. Since it came out, I think I listened to at least a song from it every week (high chances that song might be The Parchment)
Oh, and if anybody pulls that TNOTB-7th Son string of albums in this thread - ban them.