Top 10 Doomsday Devices

 
The Death Star: Grand Moff Tarkin and his Emperor intend to use this massive battle station to control the universe through fear and may have pulled it off if it weren't for that Skywalker brat. The Death Star's planet busting super laser weapon puts out as much destructive power as the liberated energy of a small artificial sun. It may not be the most efficient design but it is one of the most dramatic, which was part of the point. It tops the list because of its iconic design.

Ice-Nine: In Cat's Cradle, Ice-Nine is a substance that takes crystalline form at room temperature and has the ability to convert neighboring water molecules from their liquid to their solid state. If introduced to the water system even a small amount could freeze the entire planet. Destroying a world by making it uninhabitable isn't as sexy as blowing it up but considering all you only need enough Ice-Nine to fit in an Altoid's tin to get the job done, this method gets points for efficiency.

The Illudium PU-36 Explosive Space Modulator: Marvin the Martian intended to use this dynamite-like weapon to destroy the Earth because it obstructed his view of Venus. The PU-36 makes the list because of its name (once you have heard Marvin say "Space Modulator") and the excellently frivolous reason it was going to be deployed (Earth and Venus almost never come into alignment with Mars).

Orchid Toxin: Hugo Drax was a proper Villain with a massive lair, deadly lieutenants, scores of minions and a master plan to reshape the earth according to his twisted design. The first step in his scheme involved destroying all human life by launching 50 globes of a rare toxin from a space station. These globes would break apart on re-entry, dispersing the toxin into the atmosphere. Any plan that is ridiculously complex, seemingly impractical and involves something as esoteric as flowers is doomed to fail but gets points for style.

The Alpha-Omega Bomb: In Beneath the Planet of the Apes, the astronaut heroes flee the gorilla army into the subterranean remains of their world only to find a race of mutants worshipping a missile. It turns out that the warhead on the missile is a doomsday device capable of wiping out all life on earth. They try to warn the apes but the astronauts are killed and the gorillas set off the missile, which ignites the atmosphere and kills everyone.

Halos: In the game of the same name the installations built by an alien race called the Forerunners, the ring shaped habitable megastructures are also super weapons designed to combat an alien parasite known as the Flood. When triggered, as single Halo ring is capable of destroying all biomass in a 25,000 light year radius. If all seven installations were triggered at once the effect would encompass the entire galaxy.

Dr. Device: The Molecular Disruption Device from Enders' Game and it's sequels can destroy any object and any objects nearby, creating a chain reaction that can destroy whole fleets of starships or even planets. It is used to end the Bugger war, much to the chagrin of the hero who made its deployment possible.

Kisof's Insurance Policy: In Dr. Strangelove, when a rogue bomber threatens the Soviet Union, the Premier reveals that Russia has built a doomsday device set to destroy all life on earth if the country is ever the target of a nuclear attack. Unfortunately, there is a safeguard that prevents it from being deactivated and it was useless as a deterrent because the attack happened only a few days before the Russians planned to go public about its existence.

The Doomsday Machine: The planet killer from the classic Star Trek episode of the same name was encountered by the crew of the Enterprise while on a apocalyptic rampage. Kirk theorized that the device destroyed the race that had created it.

The Button: In the last season of the Flintstones a green alien named the Great Gazoo crash landed his saucer near Bedrock and was found by Fred and Barney. It turned out that the mischievous creature had been banished from his home planet of Zetox for creating a button that, if pressed, could destroy the entire universe. Gazoo claims he created it on a whim and had no intention of using it but it there was something sinister about the way he toyed with the cavemen that suggests he was capable of incredible cruelty.