May have to write a wall-of-text here. Bear with me.
Superheroes have always been the prime-time of entertainment, some are greatly written and others you just see for the sake of it or to see an awesome bad-ass beat up thugs and other stuff. However, in this conversation, this isn't about who is stronger more of which storyline is stronger, which character do you think is most well developed.
I have just seen TDKR, and I have to say I was pretty damn amazed. While nobody can replace the great acting of Heath Ledger as the joker, TDKR was a better all around performance (have to mention Aurora here, my condolences to those affected). With Nolan's trilogy of Batman completed, I have to say that it is perhaps the best written Superhero trilogy I have seen yet.
And while it may have not come first, Avengers made a very close second. I was skeptical at first since movies similar to this are usually not good, but I have to say I was very surprised at how well it was done. Definitely looking forward to more production from them in this department. At 3rd, I put in Tony Stark's acting as Iron Man. He is just absolutely perfect at that role and while it does have its flaws (and every series has its flaws, believe me), I think it was done well as well.
If it wasn't for Spiderman 3, I would have made the Spiderman Series in the top 5, but I am interested in the new Spiderman stuff coming out, as I believe that the new movie was well executed.