Check out these three action packed clips from Captain America: The Winter Soldier, but beware of slight spoilers.
Avengers: Age of Ultron - Casting the VFX Vendors
fxguide have created a very thorough article about the VFX vendors contributing to the massive Avengers: Age of Ultron.
The Amazing Spider-Man 2 - Featurettes
Here are two featurette videos for the upcoming The Amazing Spider-Man 2 fim.