Glitch
Pokémon Red, Blue and Yellow - One of the most famous glitches in the history of video games. By taking advantage of the hexadecimal system of the games and the save function, the player can find a level 7 Mew by battling certain trainers and traveling to certain towns in a certain order. This glitch has become very famous in the online community.  There is also the Missingno glitch, which is also famous, but will block the ability to save.