Not many thing throw me over the edge in the whole of things, but I can name a few:
Gasoline explosions: Sure they look nice and pretty, but a massive airstrike doesn't look like I just blew up a fucking BP oil rig.
Firing sounds: An assault rifle and a heavy machine gun do not make the same FUCKING noise.
Grenade detonation: A Frag grenade can not throw up a plume of dust up detonation, just no.
This one doesn't have to do much with movies, more with video games:
Gatling guns: A gatling gun does not sound like every other machine gun when it fires, by that meaning you can't hear every round firing. They make more of a roaring noise due to there rate of fire.
On another note, my Captcha is telling me to save yourself.