UT: Flak Cannon
Quake 2 WOD: Street Sweeper
Bloodborne: saw blade, Ludwigs Holy Blade, hunters axe
Horizon Zero Dawn: Tearblaster
Nier Automata: Virtuous Treaty
Xenoblade Chronicles: Monado
Berserk: The Dragonslayer
Final Fantasy 7: Buster sword

My favorite definitely is the Meredith & Co. Radius II Raygun from Xenoblade Chronicles X. Best raygun in the game and fairly cool look. 

Have other options from X, but for the sake of variety, let's say I also like the Master Sword, Gears of War' standard shotgun and the MTAR from Black Ops II, though I suposse the latter is semi-real. 

Also, if it can count, I'd include the Cobra from Age of Empires II:

The Greatsword from Dark Souls 2/3 is my personal go-to weapon in them. The weight behind the attacks and the simplistic design of it makes it pretty cool in my books.

The Hydra Splatling from Splatoon is amazing, too. It's a Minigun that's made from a Water Tank and a Fire Hydrant, and that's just cool.

Im a sucker for time manipulation stuff.....

Another fantastic weapon:  The Monado

https://pre00.deviantart.net/71d9/th/pre/i/2015/104/3/e/xenoblade_chronicles___the_monado_by_atticus_kotch-d8bqqbr.png

I second the Monado, the pistol from Halo, the BFG, and the Holy Hand Grenade.

Some others:

Torque Bow, Gears of War

Ripper, Dead Space

I used to absolutely love the rocket launcher from Quake III, was so gratifying to shoot far ahead of a distant enemy and get the timing just right :D

Kingdom Chain from Kingdom Hearts.

Rob5VGC said: Kingdom Chain from Kingdom Hearts.

Iconique

Shooting (besides splatoon ) : Sniper rifle
RPGs: Magic staff or book

Keybladewielder said: Rob5VGC said: Kingdom Chain from Kingdom Hearts. Iconique

lol Exactly. This is why I only use default keyblades when I play through the story. I'll be lenient when it comes to post game stuff since I'd like to use the Ultima Weapon.