If you want insightful game analysis on Youtube, you can't do much better than Ahoy. His crisp, even-handed commentary, historic perspective, impeccable animation and subtle British wit make me wonder how on Earth the shameless grievance mongers and jump scare jockeys of Youtube have amassed such embarrassingly large fanbases.
Ahoy's latest video is a fascinating, exhaustive look at Doom. He covers the whole series and a handful of mods as well, commenting on the game's development, history and influence. It's a great watch if you have about an hour to kill. Definitely give it a look, especially if you're impatient for the Doom reboot coming later this year.