Hard to choose just from the Ratchet and Resistance games alone. Insomniac are masters of creating fun and inventive weapons.

I will say Mr. Zurkon from Ratchet and the Auger from Resistance.

These are all among my favs as well, great picks.

I'm gonna throw in:

The gloriously overpowered pistol in Halo: Combat Evolved

The ripper from Dead Space; slicing enemies apart was so satisfying

Switch Axe from Monster Hunter; versatile and badass

The Super Shotgun from the Doom series

Orbital Ion Cannon in Turbo Overkill; rains down absolute carnage from the heavens

So you also often got the Flak Monkey "award" I see

Other pretenders to the Throne from me:

• BFG 9000 - DOOM. The original coolest gun in gaming, accept no substitutes!
• The cannon from Serious Sam. An 18. century navy cannon loaded with exploding depleted Uranium cannonballs? And you charge the shot? Whoever came up with that idea was either crazy or on drugs - probably both - and I love every second of it!

Absolutely nothing comes to mind. ;)

Aranea Spear (Stoss Spear) from Final Fantasy XV

Yamato Devil May Cry. Looks like an ordinary Katana, but it can slice reality itself. It can even divide a person into each of their individual personality traits into individual beings.

Bayonetta 2 chainsaws. You can attach them to your feet and skate on chainsaws. 

Jet Stream Sam's Muramasa in Metal Gear Rising. The blade is superheated and can cut down to the molecule. To top it off, to unsheath it, you shoot it out of the sheath like a gun.

Best weapon selection in any game for me is Resistance 3. Mutator is just 👌

Yeah the Resistance games had great weapons, Insomniac really know how to craft a creative and fun arsenal.

Dildo Bat. - Saints Row.

Cerebral Bore - Turok.

Moo 2000 launcher. - Southpark 64.

Laptop Gun. - Perfect Dark.

Mr. Toots. - Red Faction.

Half Life - Crowbar

Halo - plasma Grenade

Gears - Lancer

Doom - Double Barrel Shotgun

Turok - Cerebral Bore

GoldenEye 64 - Silencer PP7