5. Bioshock 2 - Minerva's Den DLC
Ok so if I'm being honest here, this entry isn't actually an example of the code of Bioshock 2 coming down around your ears should you be able to plug splicers perfectly with a harpoon gun. Instead it's more of an Easter Egg in the same vein, just... dammit it's so good I feel duty-bound to share it with you all today.
Throughout the sub-nautical sequel, you'll come across a terminal which has the word "Spitfire" plastered all over it and a tape recorder next to it explaining that this big hunk of glowing goodness is Rapture's very first video game!
In a manner similar to Asteroids you have to pilot your ship around the screen and avoid being shot down, and should you manage to get 9999 as your score, you'll actually crash the game!
This "kill screen" nets you a reward as well and provides a nice reprieve from the horrors of the rest of the game.