8. Mk 2 Lancer A.R - Gears of War
The Lancer is, to put it simply, the canine's scrotum. Never has a starting gun been so effective on a game. Long range, it is quite good at lowering health and downing enemies, and up close? Don't even go there. Where the Lancer becomes ethereal is in the fact that it has a chainsaw on the end. Yes, a chainsaw; presumably for chopping up the already disfigured locusts.
9. Gravity Gun - Half-Life 2
Basically, this is God in a weapon. It not only gives you the ability to move small objects, but it allows you to move damn near anything. You can pick up people and throw them. Pick up barrels and throw them at said people. You catch my drift right? I feel I don't really need to say anything more, just let your imagination run wild.