Don't get me wrong, I absolutely LOVE The Dark Knight trilogy. But, I think it's possible it's going to be dethroned soon by Iron Man. Being a big fan of the first two Iron Man films and loving the trailer for the much anticipated third film, here are reasons why I think Iron Man can be the best comicbook trilogy (should they decide to keep it a trilogy, I hope they do).
Protagonist

Everybody loves Tony Stark. I didn't really know or care much for Iron Man until I saw the movie, then I absolutely fell in love and apreciated the character more. The second film, in my opinion, only enhanced his popularity. As he says in the Avegers, "Genius, Billionaire, Playboy, Philanthropist". That is who the man behind the suit is. We like the character, we know who he is, what he is capable of and we have fun watching him. Don't get the wrong idea, everyone likes Bruce Wayne too. Iron Man 3, we see Tony in a much darker, more serious place. There might be humor in places in the movie but not as much as in the first two. Iron Man 3 is going to be the movie where, shit goes down.
Marketing
Yes, marketing as well all know helps puts asses in seats. This has always helped the movie and is a big part of it. Iron Man really amps it up when it comes to marketing. The first movie helped because he was a new hero. Now, it's pretty much garunteed that if Iron Man is in the movie, people will see it. I'm not trying to predict the future. But, Iron Man 3 is going to put even more butts in seats considering with the darker tone, people are going to wonder about the movie. Which means that they will see the movie. I can only hope the movies success will be greater than Iron Man 2. Which brings me to my next point.
Iron Man 2
People give this movie so much crap. In a way, I can see why. But overall, I think people should see that this is a good movie. It's nowhere near as good as Iron Man. But it's still a damn good, fun movie. Which was the goal for the first two movies. They were meant to be fun, family friendly movies. I never necessarily liked the idea of a hybrid villain of Crimson Dynamo and Whiplash, but it worked. It was darker than the first, but was still a fun movie. I have yet to see a valid point on why Iron Man 2 is a bad movie. It's the weakest of Phase One, but it's not bad.
Director
Jon Favreau for Iron Man 1 and 2, Shane Black for Iron Man 3. Jon Favreau did a great job at making the debut for Iron Man. They got a great director to bring the character to the big screen for his first two adventures and it worked. Shane Black, I only know him as the writer of the Lethal Weapon movies. So, I know what he is capable of in the sense of writing. I've never seen Kiss Kiss Bang Bang. I want to though because it looks really good. I think Shane Black is definitely going to pick up where Favreau left off and is going to make the most of it. They got talented people for the films, but talent isn't everything. They were careful and Favreau was a good start and Black is definitely a good replacement. Hopefully, the movie is as good as it looks.
The End?
Is Iron Man 3 the end of the Iron Man film series? It's possible and I am one who hopes it is. Not because I don't like the movies, cause I most certainly do like them. I prefer it to end in a trilogy because I think Iron Man 3 should be the end of the story. We have a solid story throughout the films, an entertaining and good protagonist, solid villains and I think Iron Man 3 is the perfect opportunity to cap it all off. You have the Extremis storyline being based off of, you have a great villain in The Mandarin (anybody else notice the ten rings in the trailer?), it's a darker movie, Tony's world is being taken from him. They've taken one of Marvel's most lighthearted and fun characters and movies, stripped it down and put his back against the wall "Dark Knight" style.
Overall: It all really comes down to prefrance in some ways. For me, I think The Dark Knight trilogy is brilliant. The Dark Knight and The Dark Knight Rises are both two of the best comicbook movies to date. But, I prefer Marvel's movies over DC and always have. I've prefered Iron Man both as a character and the movies to Batman. I think Iron Man is going to be one of the greatest comicbook trilogies out there, again should they keep it a trilogy. What do you think? Comment below, be respectful.