Every once and while marvel comics makes a short animated video trailer for some of their better upcoming comics and crossover events.
I was looking through Marvel.com's video section, watching old videos again; and I figured I'd post them here. Save some people the trouble.
Now, most of these are comic book trailers (most of which are very cool to watch), but I've also add a couple videos from the upcoming animated
Dr. Strange movie (including the opening scene), and a Colbert Report video featuring Captain America and his death.

My personal favorites are "Ultimate Spider-Man Scene" and "Previously in Civil War"