Princess Daisy of Super Mario Land. Friend and unconfirmed cousin of Princess Peach, the redhead Daisy was stated as a tomboy in Mario Tennis, her first modern appearance, and is known for her energetic, loud, and competitive character traits.
Sonic the Hedgehog series gives us Knuckles the Echidna, whose temper is just as fierce as his punches.
Nariko from Heavenly Sword. There has perhaps never been so much red coming out of one head.
Also the auburn-haired, militant steel machine, Von Kaiser.
Excepting the game versions and art which depicted her as a blonde or brunette, Tyris Flare of the Golden Axe series. A fiery redhead in that she was able to summon explosions and dragons with her magic.
Karst (surprisingly, the only Fire Clan member to follow this trope).
Tyrell (considering Garet's his father).
Eoleo the Champa (debuted in Golden Sun: The Lost Age, but grew into the personality for Dark Dawn).
Planescape: Torment features the sharp-tongued, passionate, brash tiefling thief Annah-Of-The-Shadows.
Of all the Redheads in The Witcher, Princess Adda is the one who could be called fiery. Triss has her moments but is more often the tactician in combat or politics, as does Shanni, but she is more often motherly.
House Harkonnen from the Dune games. While this trope may not be entirely noticeable in Dune II and Dune 2000, this is very prevalent in Emperor: Battle for Dune. Several of the Harkonnen people notably have red hair (including Baron Rakan, Copec, and plenty of the house's infantry) and this very house is known to be cruel even to their own. The Baron does not hesitate one bit to scold a field general who failed a mission, giving a warning like "if this inept performance continues, I'll have you skinned alive!" Indeed, when you view the first FMV cutscene for this house, you hear the previous general cry out in agony, getting tortured by a slow and excruciatingly painful death because he failed his superior leaders. In the cutscenes, Copec and Rakan have short tempers. In the first cutscene when Gunseng attempts to help his ailing father, Rakan pushes Gunseng away with a hint of anger and tells him to go away. The whole House of the Harkonnen is corrupt and only consider their own desires, hence the artificial alterations to most of Geidi Prime; hardly anything can grow there by itself and new things require the expense of older substances to develop.
Inverted in Neverwinter Nights, in which (by hair color) Aribeth is the closest thing to a redhead among all of the NPCs but is also the most rational and collected of the entire cast (until the dreams begin).
At first glance, this trope is averted in Dragon Age: Origins, where pious "good girl" Leliana is a redhead and "bad girl" Morrigan is a brunette. But Morrigan is a frosty kind of dark - sexual but not emotional; whereas Leliana is a former seductress-assassin and potentially an affectionate romance option for the player's character (whether male or female).
If Leliana becomes "hardened" due to her personal quest, she plays this trope perfectly straight from then on.
And Oghren plays the trope straight into your face from the moment you meet him. His personality alone deserves its own slot in the party selection.
Aveline from Dragon Age II also seems to be one, and various redheaded NPCs play it straight, subvert it, etc.
Pokémon example: Darmanitan, the absolutely berserk-looking daruma doll gorilla, is covered in red fur. A literal example too, as it's a Fire-type. The series has a few other examples like this.
From the Nobunaga's Ambition crossover, Pokémon Conquest gives us Kai, who has literal fiery red hair. Not in the Flaming Hair sense; this woman's hair shapes like flames when she gets angry, and looks like an explosion when she get's shocked. Fittingly, her Perfect Link is Darmanitan, listed directly above.
From the Pokémon ranger sideseries, we have Lavanna.
And Alena from Dragon Quest IV, who (despite the pointy hat) isn't even a magic user, but instead a princess who would sooner punch her problems away than act like the stereotypical princess her father wants her to be.
Tsubaki of BlazBlue is a rare example of this trope being Double Subverted. She's a redhead, but for all of the first game (where she was an NPC) she was a studious, level-headed, rather pleasant Yamato Nadeshiko. Where the double subversion kicks in is when she is introduced as a playable character with her own story in the second game: she's actually a deeply wounded Clingy Jealous Girl to her love-interest Jin. It goes so far that not only does she become a vengeful, screaming maniac whenever someone gets too close to him, she actually tries to murder her friend Noel after Big Bad Hazama convinces her that Noel stole away her chance to be with him, and she performs a Face–Heel Turn. Fortunately, Tsubaki can't bring herself to kill Noel, and later both Noel and Makoto can bring her back to the side of good..
RosenkreuzStilette presents to us Zorne Sepperin, who's a short-tempered, impulsive, and moody little girl with love affections towards Graf Michael Sepperin (whom she regards as her father despite the absence of blood ties) and a knack for creating and throwing bombs a la Bomberman.
Brooks in The Orion Conspiracy plays this trope straight to a T. She can cuss, she can fight, she can have sex, she can do a lot.
In the 1st Degree presents Ruby Garcia. She is a redhead (Captain Obvious), her first name refers to red, and she has the attitude. She is the girlfriend of the defendent James Tobin, and she wants to believe that he's not a murderer. In fact, asking the wrong questions (especially questions that make Tobin sound like a murderer) will get you an explosive outburst from her.
In what could be another double subversion, League of Legends gives us Miss Fortune. She's red-headed and passionate... but falls more into the territory of cool-headed, teasing and seductive Femme FataleMs. Fanservice, yet still has a competitive edge. That is, until she's told to use her ultimate skill, Bullet Time, in which she goes very fiery and let out a great laugh as she pelts you with bullets.
In the seventh installment of the Dark Parables, the Fairy Tale Detective meets Rapunzel's betrothed, Prince Ross. He's a red-haired, red-eyed Hunk who wields both a Flaming Sword and Elemental Powers of fire, and he's rather intense and comes across as more than a little angry. He's an extremely good person, however, and he loves Rapunzel devotedly.
Captain Lorimette, in Queen at Arms, is a regal and dignified Lady of War - but she's also very much this when her buttons are pressed.