It may not look like much by today's standards, but this was arguably the multiplayer map that popularised the online shooter, so you just take a good long look at those 50 shades of brown in front of you and show it some goddam respect! DM3 was a quintessential multiplayer arena, made up of multiple rooms (each with their own strategic advantages for you to figure out), jumping pads, and even outdoor areas - where you could admire Quake's revolutionary sky graphics before get promptly pulverised into big blocky giblets by a rocket launcher. The level famously contained all the weapons in the game, and continues to be one of the most popular maps in Quakeworld (the multiplayer-focused update to Quake) to this day, and is still widely used for high-level Team Deatmatches and Clan Wars. It's also the only multiplayer level in the game to have been designed by the great John Romero, making it a crucial map to experience for fans of game history and design.