The game: Id's seminal first-person shooter that helped establish and popularize the genre, Wolfenstein 3D was all about killing tons of Nazis. As in the recently released (and quite fantastic) Wolfenstein: The New Order, action takes priority above all else. Simply grab the biggest gun you can find, locate some of the Reich's cruelest followers, and go to town.
The most ridiculous mod: Take your pick, really. Wolfenstein 3D saw plenty of mods, some silly, some not. But one of the more twisted ones available, Pokestein 3D, poses the following question: What if the Nazi regime was composed not of human beings, but hundreds of murderous Pikachus, among other Pokemon? This is the stuff of nightmares.