Honestly by categorizing their albums into "somewhat angsty pop punk", "polished somewhat angsty pop punk", "generic pop-trash", and other genres, really by defining their albums only by genre at all, I think you have skipped over the most important part of Fall Out Boy, and the only thing that made classic Fall Out Boy, well, classic Fall Out Boy!, as well as the only thing that actually did make them original: their lyrics, and more importantly the way they delivered them.

In the days of From Under the Cork Tree ('02-'07), while MCR, Blink, and a hundred other pop-punk bands were busy emo-hating themselves and contemplating suicide, doing their best to be the flagbearers for all their fans who were too afraid to talk to girls, Fall Out Boy brought the sex back into pop-punk. The lyrics on FUtCT were furtively sly, and perfectly pop-crafted, endlessly singable, and playfully if almost goofily sexy, while still being clearly self-deprecative, all while staying just self-aware enough so as not to be cheesy. In FUtCT, they always sounded like they were actually having fun. I mean they had lines like:

"I'm just a notch in your bedpost, but you're just a line in a song..."

or

"Why, don't you show me the little bit of spine / you've been saving for his mattress... / I only want sympathy in the form of you crawling into bed with me."

Written words don't really convey his ability to sing a half-playful, half-desperately-filled-with-impossible-teenage-lust, half sardonically self-derisive I-know-I-suck-so-fuck-it-anyway delivery, and yet that so tough yet so effortless-for-him delivery hasn't been something he has really been able to replicate in the later albums-- one of the reasons I think the Save Rock And Roll singles that are all over the radio sound like a pop-punk-ified Rihanna outtake.

I mean, it's not their fault that pop completely changed during their long hiatus (Pop-punk literally died while they were away), and so of course I don't blame them for being like everyone else on pop radio, using tricks like like pitch correction, or the "the first half of the chorus only needs to be three words and then a repeating last syllable" trick (Light 'em up-up-up), or the "the second half of the chorus is simply some melody made up of 'whoas'" trick (Whoa, OH, Oh, oh oh, oh), but truthfully, I hoped for more from their comeback than just already played out pop trends.

That's why I think From Under the Cork Tree is their masterpiece. It had its' time, it had its' place. Fall Out Boy had its' time, it had its' place. They're simply not a band that should (or can, for long) really exist in the current arena of pop music.