Random love scenes where two characters who have only known each other for a few days decide to have love all of the sudden.
When the character kills thousands of red shirts, mooks, minions, but refuses to kill the main antagonist because morals or ethics.
The token minority character who only exists for the purpose of just being there.
When the main character can hit anyone with a gun, but can't hit the protagonist from 5 feet away which leads to a long drawn out fist fight.
The overused drop the gun or I kill your girl friend scene.
Useless champanions who parade with the main character, but do nothing to help him or her. Or when you have a team of swat/soldiers their only job is to follow the character around till they die, leaving the character and some random chick alone to save the day.
The antagonists monologue is a bit overused, some of them are well used.