Nobody was really exploring the concept of doing all those things with popular comic book super heroes.
You can call it whatever you want. If you don´t wanna call it formula, call it anything else you want. But the fact is that almost all Marvel films share very similar elements, that happen to be very audience-friendly.
You have a great looking super-hero, cracking jokes, acting very casual, and that´s something that attracts people. Especially those who aren´t too into the SH genre. I know plenty of people, especially girls who don´t like action or super heroes but love Iron Man because he is funny and charming and the movies have a plenty of comedic moments mixed with action scenes. This formula appeals to all kinds of audiences. It´s light, it´s simple, it´s funny, it´s full of amazing looking men and women, feels very juvinile and doesn´t create much controversy.
You don´t wanna call it formula, fine. But i go watch a Marvel movie and i know exactly what to expect. And i feel that all those elements have been placed in the movie in a very strategic way.
Batman Begins is quite simple, but TDK has a very unusual ending, where things don´t end up exactly well for the hero and for those he tries to protect. TDKR is also original in the sense that 1) I imagined everything and couldn´t predict what really ended up happening 2) It offers me a big mix of emotions. We´ve the shock of his death, the relieve of him being alive and happy and the surprise of Blake taking his place. It´s a very dynamic type of ending that feels very different from most SH movies. Oh, and it´s powerful. It´s one of the strongest points of the film, instead of one of the weakest, like what happens in most films.