[scott_s]

Movies always abuse the gun-cocking sound, and/or have characters cock (or pump, for shotguns) the guns at inappropriate times because it looks cool.

[drblast]

Or the "click, click" empty revolver sound on a semi-automatic pistol. This pretty much only happens if you're evil though.

The slide just never seems to lock back like it should unless the hero has two guns that need to be thrown on the ground before he/she walks forward defiantly and grabs two MORE guns.