Charlie Jane Anders writes:

That sequence took from the first day of the process until the very end, says White. It's one long continuous shot of the two of them working together, ending with Hulk punching Thor. For the actual punch, they put Chris Hemsworth in front of a bluescreen standing on top of a real section of a downed Leviathan that they built. And they attached Hemsworth to a cable pull that they retimed, so he could look like he was knocked sidewise. They cut a few frames out of the footage, so it looks like Hulk's punch has "instant impact," says White.

See the 23 other secrets, too.

I also enjoyed Hulk smashing Loki.

Lower quality version of Hulk punching Thor:

This was the hardest scene in the movie to get right.

Source: Weird Secrets of The Avengers That You'd Never Have Guessed

Thank you uncoolaidman for this split depth gif:

http://reddit.com/r/GifTournament/comments/2xmnnc/giftournament_battle_3_round_2/cp1gmcb

Thor should do this:

Imgur comments: http://imgur.com/gallery/Cqrh9VE

Hulk smash Black Widow:

http://pandawhale.com/post/63703/nsfw-hulk-smash-black-widow-gif

Don't forget JimB's famous Mirror scene in Contact. It's subtle. It's one continuous scene all the way through of her as a kid running upstairs to the mirrored medicine cabinet, when you find out the whole scene had been shot through the reflection of the mirror.

Greg, that's pretty phenomenal.

Still, I love a good Hulk smashing.

Thank you Crankrune for this gif:

http://reddit.com/r/HighQualityGifs/comments/1xzx2h/avengers_album/

I have an army. http://pandawhale.com/post/35383/i-have-an-army-loki-gif

Lord knows I'd smash. http://pandawhale.com/post/59416/hulk-lord-knows-id-smash-meme

Black Widow in Avengers gifs:

http://pandawhale.com/post/59542/scarlett-avengers-black-widow-are-you-kidding-im-working-gif