Captain America: the First Avenger, was a lot better than I was afraid it would be at first. I don't mean to damn with faint praise, because it was realy good, but I was really worried from the initial descriptions. They sounded like they were uncomfortable with the superhero accoutrements, but they all come in.
Chris Evans was given a tough task: Captain America could easily descend into jingoism. See TVTropes
Eagleland trope for a better explanation of the dangers. Fortunately, it's the mainline comics' portrayal: namely Steve Rogers is in the running for World's Greatest Human Being before he gets superpowers. Despite being weak and small, he determinedly fights against bullies, and wants desperately to do his part to save the free peoples of Europe. But Steve is small, shrimpy, has asthma and a bunch of other conditions, and if something worse than 4F existed, he'd be put in it.
That determination and spark inspires the maker of the Super Soldier Serum to give the body of a hero to the heart of one. In a nicely done fashion, Old World ingenuity and New World resources make an All-American soldier (and prototype of a super-weapon, honestly). But, agents of HYDRA, the German mad science division (you can tell it's Nazi Super Science, because they have a Flying WIng) kill the scientist, the last vial of super serum is destroyed, and the formula dies with the scientist (in the comics, the formula wasn't written down for fear of spies, which isn't explicitly mentioned here, small weakness).
America wants a lot of super-soldiers, not one, and so Steve can either be in a lab while they poke him with needles to try and recreate it from his blood, or go on his (excellent) stunt sequence through Old New York and join a bonds tour. He does, and they give him the comics costume. It's... well, it's hard to describe, but it's goofy but earnest how it looks. They manage to make the tights look baggy (Cap's traditional wings look better in live action as painted-on a helmet later).
Also, best explanation of the shield ever: it was a place to hide his lines he hadn't memorized yet. It works pretty well until he hits Europe, and then Steve finally gets the chance to do what he hoped to do: save a lot of people and stop a lot of pain.
The action is excellent (the CGI when there looks noticeably better than the next Spider-Man movie whose trailer is attached), the acting is good, and the script does a good job setting up things for the Avenger movie, whose trailer is after the credits. Honestly, this is purely a setup prequel and could have been done *after* the Avengers movie equally well I think, but I'm glad it showed up this summer because honestly, it's a weak year.
Best description of Avengers trailer was given by someone shouting in the theater ' I just nerded all over the floor!'
Oh: also, the trailers give the impression Tommy Lee Jones is in it for mainly fifteen minutes? He's one of the major good-guy supporting characters, and he's a lot of fun.