Source: collider.com

6. The Rest of Phase One

Iron Man 2 (until workshop scene), Thor (until he’s banished to Earth), Iron Man 2 (rest of movie), Thor (rest of movie), Captain America: The First Avenger (first and last scenes), and The Avengers (full movie)

OKAY, SO…Start Iron Man 2 where you left off, and keep watching until right around the scene in which Coulson visits Stark’s workshop. Cool, now stop that, and start watching Thor. Watch right up until Thor is banished from Asgard and sent to Earth. Switch back over to Iron Man 2. Coulson will get a call from Fury about a wormhole opening up over New Mexico, and he’ll take off.

Finish Iron Man 2 and that post-credits scene as well. Coulson finds the hammer…Aaaaaaaaaand switch back to Thor, and finish that one off as well (If you read the supplemental comics, you’re probably supposed to watch Incredible Hulk interwoven with these two, but it works just as well like this.).

After you’re done with Thor, watch the first and last scenes of Captain America: The First Avenger. BOOM, Cap’s back. And now we’re ready for the big fireworks display. That being The Avengers. Feel free to watch that one from beginning to end. And be proud of yourself.

You just finished Phase 1.