Badass Finger-Snap

When a character need to do something impressive, they'll often do it with a snap of their fingers. Sometimes it's just a signal for Mooks to carry out a Villain's orders, but sometimes the snaps themselves have magical powers.

Fridge Logic makes one wonder about the "orders" one. How much time is spent training the mooks whether the finger snap means "bring the suitcase of money", "kill them" or "get me something to drink?"

Examples of Badass Finger-Snap include:

Anime and Manga

Fullmetal Alchemist: Roy Mustang can cause fiery explosions by snapping his fingers, using specially-made gloves to generate a spark.
G Gundam‍'‍s Domon snaps his fingers in order to summon his Gundam.
An episode of Bakugan had one of the baddies cause seemingly inexplicable combat events by snapping his fingers. he was actually signaling his invisible ally.
Wei in Darker than Black has a Bloody Murder power activated in this fashion. He drips his blood on something or someone, and the instant he snaps his fingers, there is an explosive/teleportation effect signaled by a flash of light.
Cinque's introduction in Magical Girl Lyrical Nanoha StrikerS has her throwing knives at the Administration Bureau's shield generators and snapping her fingers to detonate them.
In Tiger and Bunny, criminal NEXT Jake Martinez activates his force field powers by snapping his fingers. The results vary but are almost always painful for whoever he targets.
Giant Robo has a villain, the Fabulous Fitzgerald, who can cut anything in half by snapping his fingers at it. Watching him take apart a base and all its troops while practically dancing his way through the flame establishes this character as a badass and psychopath.
An early episode of Code Geass has Zero unveiling a massive poison gas bomb behind him with a dramatic fingersnap... and instantly taking hostage hundreds of civilians who have no idea what the contraption behind him is. It's not a chemical weapon, though; just a smoke bomb.

Comic Books

"Snapper" Carr, sidekick of the Justice League of America, eventually developed the power to teleport, but only when he snapped his fingers. (Thus being temporarily depowered when his hands were cut off.)
Hunter Zolomon, the second Zoom, used his "speed" powers to create deadly sonic booms, which he activated by a simple snap.

Fan Works

The Hill of Swords gives us a beautiful moment in the last fight where Shirou stops playing around and unveils Unlimited Blade Works, with all that entails.

In a move I stole straight from Gilgamesh, I raised my left hand in the air as I turned away, focused once more on my destination, and I snapped my fingers once. Above me the gears of my soul hung in the sky churned once with a noise like the heartbeat of god. And from the sky a rain of silver flung itself down upon my foes.

A very notable case in Harry Potter and the Methods of Rationality, where Harry snapping his fingers very quickly suffers from Memetic Mutation to the point where most of the children believe he can do anything by snapping his fingers. He even uses a hand ready to snap its fingers as his coat of arms for his army.

Film

Disney's Mary Poppins. During the "Spoonful of Sugar" segment the title character starts magically cleaning up the room by snapping her fingers, and then the children start doing it. Watch it here.
Pixar's A Bug's Life. Hopper does this with all four of his hands when he's commanding Thumper.
Ben Stiller's character in DodgeBall: A True Underdog Story snaps his fingers to command his henchmen throughout the movie. Very much Played for Laughs.
In Oliver and Company, when Sykes snaps his fingers, his Doberman Pinchers attack Fagin (and Dodger, when he steps in to save his master) in the warehouse until Sykes snaps his fingers again.

Literature

In Harry Potter, Dobby uses his magic abilities by snapping his fingers, which also creates a little spark effect.
Played with in Eric where Rincewind thinks he has gained the ability to do a Badass Finger-Snap (to his and the reader's great surprise) to grant wishes. However it is really Hell's Evil Chancellor who is doing the magic and just making it coincide with Rincewind snapping his fingers.

Live-Action TV

In Doctor Who, Series 4, in the Episode Voyage of the Damned, the Doctor snaps his fingers to have two of the angel-robot dudes lift him into the bowels of the ship amid explosions and fire.
- He later discovers he can open the TARDIS doors with a snap of his fingers, which he's used once as 10 and several times as 11.
On Star Trek: The Next Generation, Q's snapping can do all sorts of things, like fling the Enterprise all the way to the Delta Quadrant. To be fair, he's omnipotent, so can do anything he wants with any gesture he wants; he just snaps his fingers to look nonchalant while he does it.
In one episode of Burn Notice, Michael Weston convinces a gang of hardened Latino criminals to help him. He does this by snapping his fingers, at which point his careful planning will result in the other members of his crew (Sam Axe and Fiona) causing something dramatic and incredible to happen, like a door exploding; he essentially intimidates them into helping him. At one point, he has to improvise, and he bluffs by holding up his fingers, ready to snap them. By now, the gang is so afraid of what his finger-snaps cause to happen, even if they are reasonably sure that he's an still ordinary mortal man, that they quickly acquiesce to his demand without him having anything in place. At the end of the episode, as we cut away from the gangers from the last time (Michael's plotting having resulted in them taking control of a large turf from an arguably much-worse cartel,) the gang's leader snaps his fingers as he walks away from the scene of the confrontation, full of new confidence and most likely new ideas.
Angels and Demons in Supernatural snap their fingers for several purposes. Whether to teleport, pull someone towards them, or to reduce someone to Ludicrous Gibs,

Tabletop Games

Hackmaster Basic/Advanced. A mage can cancel any spell they've cast by snapping their fingers (Dismiss Enchantment spell, Knights of the Dinner Table #146).

Video Games

In Kingdom Hearts II, Saïx snaps his fingers to summon more Nobodies to fight Sora and Company.
- In Chain of Memories Axel burns somebody up with a snap.
Evie characters that specialize in scythes in Vindictus can learn two major skills that can take enemies out with one snap of their fingers. The first skill, Bloody Thread, surrounds up to four mobs with thread and when Evie snaps her fingers, the thread contracts For Massive Damage. The second skill, Mark of Death, has her marking up to four mobs, getting the soul from one, and when she snaps her fingers, the souls from the mobs marked are released from the body. Scythe Evies especially love using these skills as a way to finish off bosses.
Shiva's Limit Break from Final Fantasy X. She encases her enemy in a solid block of ice, then shatters it by snapping her fingers.
Doctor Doom in Marvel vs. Capcom 3. He can snap his fingers to summon his Cool Chair, or his HIDDEN MISSILES! Both of which can happen on any stage.
Touhou Soccer gives us Mima and her Twilight Spark, which she fires with a snap of her fingers.
Ghirahim in The Legend of Zelda: Skyward Sword snaps his fingers whenever he uses powerful magic like creating fences around the Sealed Grounds, bringing a boss to life, or creating a sword to fight Link with.
In Super Mario RPG, Bowser's magic is triggered by him snapping his fingers.
Dimentio in Super Paper Mario would cast his magic by snapping his fingers. Explosions usually followed.
Manfred von Karma from Phoenix Wright: Ace Attorney often snaps his fingers for dramatic emphasis.

Western Animation

Jinx from Teen Titans uses this to activate her bad luck powers.
As part of the Actor Allusion to Q, Discord of My Little Pony: Friendship Is Magic sometimes snaps his fingers whenever he warps reality.
- It's worth noting that this is one show where one could not count on the characters actually having fingers to snap... on the fingers of one hand. Lauren Faust's notes on him claim that she "cheated" a more expressive arms/legs combination out of the original dragonlike design.