2) Alexis Denisof
Joss Whedon is known for working with the same core bunch of actors in his TV shows and movies. When taking the reins of The Avengers, the writer-director couldn’t help but give one of his most frequent collaborators a tiny role. Even the most hardcore Whedonites wouldn’t notice this one, however, as the actor is completely unrecognizable.
Remember the gravel-voiced lackey who explains about Loki’s plans to take over Earth to his boss Thanos at the beginning and end of the film? Well, the character – mysteriously named The Other in the credits – is actually Alexis Denisof, who’s most known for playing Wesley Wyndam-Price in Buffy and Angel. He returned to the role for Guardians of the Galaxy, where The Other was murdered by Ronan The Accuser – thereby ending Denisof’s MCU career before it had even really started.