Before Hollywood's biggest movies have even entered production, casting directors, scriptwriters and special effects teams spend an incredible amount of time auditioning, storyboarding, and shooting test footage to ensure they have every angle covered. Can you imagine Nicholas Cage as Superman? What about an Indiana Jones movie starring Tom Selleck? These were once very real possibilities, as evidenced by revealing casting videos and deleted scenes uploaded to YouTube.

io9 has compiled a list of some of the most interesting screen tests, auditions, and alternate scenes from a number of popular movies and TV shows from last few decades. Your favorite heroes might have looked and behaved very differently should these tests have been successful — like if Matthew Fox had been chosen to play the role of Sawyer instead of Jack in Lost — but we can enjoy them safe in the knowledge that they almost happened.