It's always cool to get a peak behind the curtain on games, especially when we see stuff we weren't supposed to.
That's why I found this video from Gamecheat13 fascinating, even if the contents he found aren't stellar. After rummaging around on the Halo 3 disc, the YouTuber found several unused cutscenes. There is nothing super important here, just a couple of innocuous exchanges between characters. Oh, and a strange Johnson tutorial video where he yells at you for not knowing what an aspect ratio is.
Still, I think it is pretty interesting.
Thanks to VG24/7 for pointing it out.