From the choices above it'll be the crossbow/tomahawk.
But the choices above are a bit flawed in that they seem concerned with the realistic shooters only and Blackops specifically.
The first thing that popped into my head when I read the title was Unreal Tournament's Ripper. It's only real use is throwing people off cliffs with the alternate fire and you have to be pretty spot on with your aiming to make it work. Plus as far as I know its the only gun in an fps that allows you to headshot and decapitate yourself (the blades from its normal fire bounce off walls).
But the choices above are a bit flawed in that they seem concerned with the realistic shooters only and Blackops specifically.
The first thing that popped into my head when I read the title was Unreal Tournament's Ripper. It's only real use is throwing people off cliffs with the alternate fire and you have to be pretty spot on with your aiming to make it work. Plus as far as I know its the only gun in an fps that allows you to headshot and decapitate yourself (the blades from its normal fire bounce off walls).