Unexpectedly hilarious! Sound kicks in at 0:45s. [Video link]
It's not common for Marvel to feature blooper reels as part of their DVD/Blu-ray special features because obviously, fictional superheroes and the people who play them are supposed to be perfect. However, Joss Whedon made this movie, and if there is anything he's taught us about gifted people tasked with protecting the universe from evil, it's that they are far from perfect. Sometimes, hilariously so. And so we have an Avengers
blooper reel. Watch for Colbie Smulders "trying something out" for one of her more emotionally involved moments. UPDATE: Sorry about the YouTube video that ended up pulled this afternoon. You can watch the reel at io9.
(via The Mary Sue