Edward "Whitebeard" Newgate (One Piece); when Akainu killed Ace
Saitama (One-Punch Man)
Kenshin Himura (Rurouni Kenshin)
Meliodas (The Seven Deadly Sins)
Shachi Kamishiro (Tokyo Ghoul)
Pharoah Atem/Yami Yugi (Yu-Gi-Oh!)
Kurama (Yu Yu Hakusho)
Asura (Asura's Wrath)
Doomguy/Doom Slayer (Doom series)
Sephiroth (Final Fantasy VII)
Kratos (God of War)
Ryu Hayabusa (Ninja Gaiden)
Jake Muller (Resident Evil)
Albert Wesker (Resident Evil)
Even with his easy-going attitude, Son Goku (Dragon Ball Z) felt rage at the loss of his friends when he faced Nappa...
...and even with his heart tainted of seeing his best friend, Krillin, die before his eyes, it was a quiet but fierce battle against Frieza.
Meliodas (Nanatsu no Taizai) is called the Dragon Sin of Wrath due to his dangerous and destructive temper. After training in Istar, he has not only regained his full power but achieved a state of quiet and controlled fury through projecting it at a constant rate in battle.
Even in their younger years, as part of the Hyuga Clan (Naruto) Neji and Hinata fight with controlled tempers and careful precision.
Uchiha Clan members such as Madara (Naruto), were notoriously gifted fighters as he took on multiple opponents without a shred of emotion.
Though usually carefree, Monkey D. Luffy (One Piece) can still be silently yet extremely enraged.
Despite Doflamingo's (One Piece) relaxed attitude, he does have a temper, shooting Law three times, his plans for SMILE ruined, being dethrone, Luffy's interference and desperation to kill him, he still retains his trademark smile because he couldn't get any madder.
Saitama (One-Punch Man)
Kurama's (Yu Yu Hakusho) anger made him act on the impulse to kill Gourmet and sentencing Toguro into a lifetime of suffering.
Judge Sheko (DC Comics) a scorned judged turned vengeful red lantern who maintained lucidity after her rage monsterized her body & mend.
While others view it as a weakness, Jason Todd/Red Hood (DC Comics) has focused his bottomless rage into a disciplined and deadly fury.
The Challenger (Marvel Comics) is an Elder of the Universe scorned by the usurper of his name, boasting incredible power tempered yet honed by his eons spanning fury.
In his Green Scar persona, Bruce Banner/The Hulk (Marvel Comics) learned to focus and control his anger, remaining calm and collected while becoming the most powerful Hulk incarnation yet.
Enemies and allies alike agree that Peter Parker/Spider-Man (Marvel Comics) is at his most dangerous and terrifying when he's so angry he stops his trademark wisecracks...
...such as when he hunted down the Kravinoff family for putting him and his "spider family" through torment, ripping the flesh off of Sasha Kravinoff's face while remaining calm and collected.
While it happened only twice that she had no control over her anger, Princess Celestia (My Little Pony Series), combined with her kind-hearted nature and level-headed nature, she tends to be intimidating and unnerving even if her anger is under control whilst barely raising her voice.
Princess Unikitty (The Lego Movie) has a powerful anger which she keeps intact with thinking positive.
Rupert Giles (Buffy the Vampire Slayer) was consumed with rage after Angelus killed Jenny Calendar, burning down his lair and beating him with a flaming baseball bat while remaining calm and collected.
By his own admission, Bruce Banner (Marvel Cinematic Universe) is "always angry", allowing him to freely shift into the Hulk.
By using the pain of losing his wife, the loss of his limbs and his new agonizing cybernetics, Darth Vader (Star Wars) was of the most powerful Dark side users in universe.