"I should warn you, it's been done."
—Superman to a mook about to shoot him, Superman: The Animated Series, "My Girl"
"Y'know, I remember watching the old Superman TV series with George Reeves, and the bad guys would always shoot at Superman, when he showed up. I used to ask myself, why? They know it's not going to hurt him, at most, it'll piss him off, so why shoot at him? You know what it comes down to? The bad guys are always stupid. Dirt-stick-stone stupid."
—Pyre, Rising Stars
(bad guys fire at the scary metal colossus for about fifteen seconds)
"Were they not briefed?"
"...you don't die, do you?"
"So Slater tries to shoot the guy but apparently bullets are just like Milk Duds being thrown at him."
Would lasers or tactical nuclear weapons have any effect? Cthulhu's so damn big he'd make a grizzly bear look like a kitten embryo.
—Chris in Nightmare's Disciple by Joseph S. Pulver, Sr.
"Superman!" the criminals would say. This was the signal for Superman to put his hands on his hips so the criminals could shoot their revolvers at his chest, an effort that always caused Superman to adopt a bemused expression because, as a native of Krypton with special powers, he knew that the criminals were shooting blanks.
Cop 1: This is hopeless! We might as well be throwing candy corn at them!
Cop 2: So what do you want to do? Give them the city?
Downpour: Nobody harms my sister. Nobody!
(blasts Aquaman with a wave of water)
Aquaman: (completely unfazed) King of the seas, remember?
That's for wasting ammo!
—Max Damage, punching a guy who just tried to shoot him.
Oh, you're kidding me. You do not open up your huge war machine to shoot at the bulletproof robot.
—Atomic Robo, Robo and Goliath
In spite of the fact that tanks have repeatedly been shown to have no more effect on Godzilla than a shampoo and creme rinse, they still get trotted out with every new monster attack, rolling shakily over the canvas landscape and firing their little sparklers. The reason for this, I'm guessing, is political. If the prime minister fails to send the tanks, in the next election his opponent will run ads saying "In the last Godzilla attack, the incumbent failed to send out the fakey-looking plastic tanks to protect us. My opponent is obviously soft on giant monsters!"
"Kind of hard to land a hit when you are intangible!"
—Ben Tennyson to True Assassin, Fate Stay Night: Ultimate Master