If you are a Joss Whedon fan then this theory that a fan on imgur came up with will blow you away. Take a look at the image below and tell me id doesn’t make sense. The movies in order of appearance are Buffy the Vampire Slayer, Angel, Cabin in the Woods, Firefly and Serenity.
Joss Whedon is of course busy with the new Avengers: Age of Ultron and the Marvel TV series Agents of Shield.