I gave it an "A". I wish it had been longer. I saw it in 3D, and I liked the 3D.
I wanted just a bit more backstory on how the Red Skull located the Cosmic Cube, not that it would have had a significant bearing on events, although a hint of exactly what became of him would have been nice. Hopefully all outstanding questions will be answered in the Avengers.
I also would have liked to see a bit more of the early adventures of Cap and team with Bucky.
I felt something for Steve, so the movie definitely succeeded in creating a character with whom I could identify. Job well done on that score.
My dad was with me, and I think he liked it even better than I did, which was a shock to me.
My only complaint was that I didn't like how his shield was, without any technobabbly explanation, immune to the Cosmically-charged energy weapons [whose effect I thought was really well done]. Mere mention that vibranium was, say, forged from a meteorite, or from matieral believed to come from outer space, would have gone a long way to make me feel better about that. If they said vibranium is thought to have come from outer space in the film, I missed it.
The Avengers trailer attached to the end of the film was enjoyable.