None of the other big-time GA books have the combination Cap #1 has:
*No.1 issue of a series devoted to that specific superhero.
*First appearance of a classic superhero.
*Origin of a classic superhero.
*First appearance of that superhero's arch nemesis (Red Skull).
*Classic cover.
*Impressive cover artistically/visually.
Action #1 -- an anthology series, one hero story, classic but artistically simple cover.
Tec #27 -- an anthology series, one hero story, no origin whatsoever.
Superman #1 -- no 1st app., mostly reprinted material, no notable villains.
Batman #1 -- not the 1st app., of the title character.
Marvel #1 -- No top-tier characters, no noteworthy villains.
In those respects, no other GA book is in Cap #1's league. And the combination of factors listed above are, to me, much more than "Oh yeah, that's neat" kind of stuff.
You say that in "those respects, no other GA book is in Cap #1's league", and that may be true based on the criteria that you defined, however based on the criteria I might define the same could be said about Action #1...
I don't usually put this much thought into ranking the top books based on personal desirability, but here goes...
Although I actually perform a calculation, I suppose that I typically implicitly look at the following criteria, in the order shown, when ranking the desirability of the best of the best Superhero books:
My highest weighted criteria:
(1) First Appearance of 1st Tier Superhero
(2) Cover Related: 1st cover appearance of Superhero &/or Classic Cover
(3) 1st time origin story told?
Bonus points if the book has this stuff:
(4) Arch Nemesis included?
(5) Is it a #1 issue of a book that has one or more solo stories in every issue for the Superhero in question; a bit of a bonus if the entire book is devoted to the Superhero in question
(6) Other noteworthy factors not covered above
I suppose I then implicitly assign ratings to each of the criterion above and then multiply those rankings by the applicable criteria weighting in order to arrive at the overall ranking of a given book
Based on the criteria I have identified above:
Action #1 -- Meets all of my criteria above and ranks high in each category IMO (bonus points for being a #1 issue and for being the 1st major ongoing superhero book)
Tec #27 -- No origin story, and while Bats appears on the cover, the cover isn't quite as classic as some of the others IMO. Very high ranking for criterion #1 / no noteworthy bonus points.
Superman #1 -- Not Supes first appearance and not the 1st origin story (although it is expanded on a bit). Bonus points for being a #1 issue and for being the first book devoted entirely to a superhero.
Batman #1 -- Not Bats first appearance, nor is it the first time his origin is told (although it does have a very early / very classic reprint). Borderline classic cover IMO (personally I'm not a big fan of Robin on the cover ). Big time bonus points for Joker first appearance and some more bonus points for being the #1 issue of the first book devoted to Batman.
Marvel #1 -- 1st newsstand appearance / origin of Subby and 1st Human Torch, but neither are what I would call 1st tier superheros. Classic cover with the Torch but no Subby. Bonus points for being Marvel #1.
Cap #1 -- 1st appearance and origin of Cap, and while his stock has certainly gone up of late, I still wouldn't put him in the same category as Batman or Superman. Classic cover. Bonus points for being a #1 issue devoted to Cap and for the 1st appearance of the Red Skull.
If I were to actually work through the calcs (assigning weights to various criteria and ranking each book against each criterion, and then adding up total score for each book), based on my weightings / rankings, I believe I would probably end up with the following rankings:
Action #1
Tec #27
Cap #1
I'm sure everyone else has other criteria that they look at, and assign different weightings to their criteria than I do, if they were to take the time to try to explain how they personally rank various books...
P.S. Having said all that, I guess I don't always follow my own "rules" as my formulae above would probably rank All-Star #8 above Sensation #1, however I actually prefer Sensation #1 over All-Star #8
I like Sensation #1 over All Star #8 as well, I also like Wonder Woman #1 over All Star #8.
But Cap is not a first tier character. So putting him at #3 I can't get on board with
By what criteria is Cap not a first tier character?