So as I understand it. The Incredible Hulk from 2008 was the tie in to The Avengers. The first Hulk from 2003, was the adaptation much like the Toby McGuire Spider-Mans. That being said, I don't think either Hulk film was all that great, but The Incredible Hulk followed the book story line better (not a comic reader either, just researched the backstory).
As for the Marvel films, I've been pleasantly surprised with all of them. Thor was my least favorite.
Also, Black Widow and Hawkeye don't have super powers, they are the highly trained SHIELD agents that unite SHIELD to the Super Heros for the Avenger Initiative.