I've never actually played any of the Five Nights at Freddy's games, but it's been fun watching MatPat trying to dissect the story as the games have come out. He finally believes he has the story finally solved.

The final video (the main one for this post) is the final theory, and is good on it's own, but it was also a fun journey watching MatPat and the Game Theorists try and figure the games out as they came out, so I'd recommend watching the whole playlist:

https://www.youtube.com/playlist?list=PLOl4b517qn8jl4Lw8H8cDrDkGwf1FtC7I

And of course, now that the story is "solved," there's a new image at http://scottgames.com/ that hints at more on 12/22/15 lol.