Iron Man (movie)
The Iron Man movie was kind of a surprise hit. Pretty much nobody but us comic fans knew anything about him, and superhero movies can be pretty hit-and miss.
When I heard about Robert Downey Jr. being cast as Tony Stark I thought, "Yeah, I can definitely see that working! That's pretty much perfect casting!" When the first pictures of the Iron Man armor were released I thought, "Whoa! I have to admit, that looks good! Pretty faithful to the comic, too!" That always makes us fanboys happy.
Anyway, John Favreau did a great job directing a movie that had heart, action, and was actually fun, too. Tony had some trouble testing those prototypes, didn't he? :)