Wow, thats a first you dont see too often
Well, I think it's a brilliant movie. I just love Shane Black's writing and storytelling, and he didn't pull any punches (as far as it was possible in the 'MCU').
Iron Man 3 is a fun and action-packed rollercoaster ride, with a focus on characters and story (which is rich and varied, and actually goes to many different places), instead of fan-service. Black pulls the rug from under your feet, while staying true to the heart of the Iron Man mythology (including the Mandarin, which is actually a very fitting and smart adaptation, and completely misunderstood by most fans, who can't see beyond the Trevor Slattery deception - which wasn't the point at all).
I think it's the best written one, and I just love the unique tone, which balances superhero action, biting satire, paranoia, the Michael Crichton-style science-fiction thriller and even a little Christmas whimsy.
It's an incredibly satisfying and satiating package, and I love every second of it.
Shane Black did it again, that ol' fox!
And as a bonus: I love the atmospheric cinematography by John Toll and the majestic musical score composed by Brian Tyler.