Most Badass Weapon in a game

[Macgyvercas]

Obligatory BFG-9000 response.

Seriously, that weapon kicks ass, even if it does eat ammo like trail mix.

 

[Ninjat_126]

I'm a fan of the Automatic Shotgun from Metro 2033.

http://metro2033.wikia.com/wiki/Automatic-Shotgun

 

[Rayne870]

This http://wiki.runestorm.com/index.php?title=Dark_Star of course I can't find and image for it...but the description is pretty badass.

 

[LightspeedJack]

Now that is sweet.