Best Sci-fi/fantasy weapon

[Cool_Porygon]

What is your favourite?
For me its got to be lightsaber or the One Ring.

 

[Judge Mandolore Shepard]

When it comes to my favorite sci-fi weapons, here are some of my favorites:
Series 4 De-Atomizer (Men in Black)
Lightsaber (Star Wars)
Gravity Gun (Half-Life series)
D-17m (Star Wars Republic Commando)
Energy Sword (Halo series)
M-76 Revenant LMG (Mass Effect series)

Now for some of my favorite fantasy weapons:
Glamdring (Lord of the Rings series)
Narsil/Andúril (Lord of the Rings series)
Falchion (Fire Emblem series)

 

[Her]

oh as if isaac clarke's plasma cutter isn't number one
well
bar the lightsaber
but i mean.

 

[moon]

Oh wait, that isn't a weapon.

Probably lightsaber (:

 

[Mab]

the thought bomb from a few of the expanded universe star wars books.
basically kills any force-sensitive people on the entire planet and traps their souls for eternity

 

[Lunar]

I am insisting the Sonic Screwdriver is a weapon and saying that

 

[Adam Levine]

The Monado, in its third form.

 

[Arsenic]

Magnetic Accelerator Cannons in the Halo universe! Good luck stopping a 3,000 ton slug going 12,000 kilometers per second. Heck even if you somehow did, the kinetic energy from the slug would theoretically vaporise whatever stopped the slug! So go ahead try and deflect it with your lightsaber!

Of course that's the power for the station built version (a cannon so big they mount the station to the gun) ship based cannons are less powerful, but still very destructive, launching a 9.1m slug at 3000 kilometers per second. Still enough punch to destroy mostly anything in a few hits.

Even smaller variants exist as well! The famous vehicle or turret mounted Gauss Cannon is a devastating scaled version of this tech used against structures or more normally, vehicles. They even have a Man portable version for engaging vehicles and heavily armored infantry simply called the Railgun.

I think why I love it so much is because of how realistic and feasible this weapon is as well as how devastating it can be. In fact the U.S navy is already experimenting with it. Even the science is easy to understand, you have cannon, but instead of a barrel, you have 4 groups of magnets along guides acting as a barrel. To fire, the closest set of magnets are powered, pulling your metal slug towards them, then powered off while the next 4 are powered on, repeat till its left the weapon and you have a high velocity round of death.