Dark Knight Rises has been seen as an allegory for occupy wall street
It's funny you say that, because it's completely false. Sure, one can shoehorn such an allegory onto the DKR (and maybe it wouldn't be a stretch of the imagination), but Nolan himself has said that this interpretation never entered his mind. The movie was never intended as such. The intention was to finish what he started with Batman. The sad part is that he completely misrepresented the Batman mythos in the process.
Since you are not a Batman fan I am not surprised TDKR is your favorite Batman movie as, of all the trilogy, it strays most from the Batman mythos. It is not a movie for Batman fans, but rather an accessible post-9/11 action flick that appeals to the masses. As a comic book reader and fan of superheroes, I expect the same I want from all good movies (good writing, acting, direction), but also expect that they stay true to the characters. Nolans trilogy got further and further away from the latter, and because of this I find it leaves me wanting.
I am not alone in feeling that we still have yet to see the definitive portrayal of Batman on the big screen.
They are certainly darker than the Iron Man films, to argue otherwise is insane
I agree that Batman is a darker character in that he is cold, calculating and brooding. Gotham is a dark place. The films did represent his reclusive, obsessive nature even. But what you arent getting is that THIS darkness (which I have just described) is all tonal. TDK trilogy is NOT, however, any darker from a thematic standpoint than, say, Iron Man. And darker, in this sense, I think we can say translates to more mature or adult in nature. Now, they both explored adult themes. For example, Batman Begins and Iron Man both explored escalation as a theme. Escalation; This idea that the more advanced the military, police force, or superheroes get (from a weapons standpoint), the more advanced the resistance gets. TDK trilogy never fully explored it though. Only hinting at it at the end of BB. The Iron Man movies continued to explore this theme in the 2nd movie with Ivan Vanko coming out of the woodwork to challenge Iron Man on a national stage. This went to show Tony Stark that he now would always have new, stronger, more dangerous and advanced competition waiting in the wings. Such a theme is relevant to us now with all the WMDs popping up in countries across the globe and threatenting the existence of humanity as we know it. However, we see in TDK that this theme takes the back burner in favor of chronicling the rise of fall of District Attorney Harvey Dent and the battle for the soul of gotham. In this sense, TDK is really more of a good guy bad guys story at its heart, which could be likened to your Lethal Weapon reference.
Now, whichever story you prefer is up to you. It's obviously completely subjective as to which you enjoy more. But it's plain to see that Iron Man explored some mature themes all the same, with escalation as just one example. And in this case it actually explored its theme further. And, as ANOTHER reason, this could be why Iron Man is just as "great" franchise as TDK trilogy. Good movies explore their themes fully.
I think the Dark Knight are along the lines of Citizen Kane or Casablanca
You're entitled to believe that, and I would defend your right to feel that way to the death, but it's wrong either way.
and Marvel's offerings are more like your traditional action films, like Die Hard or Lethal Weapon, full of one liners, big time action, explosions, etc.
Yeah, and TDK movies weren't full of one-liners? Those jokes were just so bad that the punchlines haven't landed yet. I love Batsy, but he's just not known for his jokes.
I think some of those jokes from TDKR are still floating in space somewhere around Saturn by now.
And even if movies like the Avengers and the Iron Man movies weren't mature thematically (which they are), I could easily settle for them being like such classic entertainment as Raiders of the Lost Arc, especially in their rewatchablility (did I just make a word?). I'll watch Avengers 30 times for every time I watch a classic like Citizen Kane. But isn't that why we're comic fans?
I took my kids to see Avengers with me at the theater. We also watched all the Marvel Movies on Neflix to get amped.
By the way, THIS just makes you an awesome parent! Props, seriously.