Users have glaringly, obviously and super/unnaturally superior reaction speeds over other beings in their universe because their capabilities are pushed beyond the natural level, making them able to react faster than regular beings (in that verse).
Tony Stark/Iron Man (Marvel Comics); via the Extremis serum
Captain Marvel (Marvel Comics)
Carnage (Marvel Comics)
Deadpool (Marvel Comics)
Green Goblin (Marvel Comics)
Hyperion (Marvel Comics)
Monet St. Croix (Marvel Comics)
Nightcrawler (Marvel Comics)
Quicksilver (Marvel Comics)
Sentry (Marvel Comics)
Spider-Girl (Marvel Comics)
Thanos (Marvel Comics)
Thor Odinson (Marvel Comics)
Adam Warlock (Marvel Comics)
Venom (Marvel Comics)
Vision (Marvel Comics)
Shoko Kamimine (Medaka Box)
Yuki Nagato (The Melancholy of Haruhi Suzumiya)
Various Characters (Naruto)
Various Characters (One Piece)
Various Characters (One-Punch Man)
Point Man (F.E.A.R. Series)
Various Characters (Solo Leveling)
Sonic the Hedgehog (Sonic the Hedgehog)
Shadow the Hedgehog (Sonic the Hedgehog)
Knuckles the Echidna (Sonic the Hedgehog)
Various Characters (Sword Art Online)
Albert Wesker (Resident Evil); after his mutation
Alopex (Teenage Mutant Ninja Turtles)
Cendrillon (Toaru Majutsu no Index)
Various Characters (Tekken)
Chase Young (Xiaolin Showdown)
Wuya (Xiaolin Showdown)
Hannibal Roy Bean (Xiaolin Showdown)
Various Characters (Boruto: Naruto Next Generations)
Kron Stone/Scorpion 2099 (Marvel Comics)
Berserker Armor (Berserk)
As the strongest vampire, Dracula's (Netflix's Castlevania) supreme reflexes allow him to counter his son Alucard's speed and catch him by the face.
When wearing the Berserker Armour Guts' (Berserk) already incredible speed and reflexes are increased to near a supernatural level as he dodges an Apostles' attacks.
Having honed them to astonishing levels, Son Goku's (Dragon Ball series) reflexes boarded on the supernatural as he can easily deflect multiple ki attacks with his bare hands...
...dodge powerful strikes from opponents like Nappa, a mid-class Saiyan warrior...
...and whenever he transforms into a Super Saiyan, his reflexes increased to the point of outmatching deadly opponents like Frieza...
Having had an incredible amount since he was a child, Vegeta's (Dragon Ball series) reflexes have been supremely impressive as he can easily intercept attacks from opponents like Pui Pui...
...and Broly while a Super Saiyan...
As a Half-Saiyan and a trained martial artist, Son Gohan (Dragon Ball series) has tremendous reflexes as he catches machine gun fired bullets with one hand...
...and even while blinded, he can flawlessly still fight with ease.
As a Namekian and powerful martial artist, Piccolo's (Dragon Ball Z) reflexes are near perfect as he can flawlessly dodge strikes from an opponent like Android 17 while doing a backflip and handstand...
As a Half-Saiyan and a trained master martial artist, Future Trunks (Dragon Ball Z) has incredible reflexes as he deflects ki attacks with ease...
...sheathe his sword without even looking...
...and as a Super Saiyan form, he can effortlessly dodge ki blasts from the Androids.
Frieza (Dragon Ball series) is fast enough to block blows from Dyspo who has Supernatural Speed.
While already having incredible reflexes, Cooler (Dragon Ball Z) in his Fourth Form possesses even more potent reflexes...
...as he could swiftly evade and counter attacks from Son Goku even while using the Kaio-ken.
Kid Buu (Dragon Ball Z)
Despite his glaringly large size, Broly (Dragon Ball Super) can easily counter high-speed attacks from a Super Saiyan Blue Son Goku during their fight.
An assassin of the highest caliber, Hit (Dragon Ball Super) has formidable reflexes to compliment his Time-Skip ability.
As the World's Greatest Swordsmen, Dracule Mihawk's (One Piece) mastery over the Gentle Blade style allows him to deflect incoming bullets off the edge of his sword with incredible reflexes.
With reflexes worthy of his name, Monkey D. Luffy (One Piece) possess incredible reflexes as he dodges the attacks of a Six Powers master like Blueno with ease...
...and after 2 years of training, they have drastically improved thanks to his mastery of Kenbunshoku/Observation Haki which enables him to dodge a Pacifista's deadly laser barrage ...
...large liner attacks like Hody Jones' Shark Bullets technique...
...and due to fighting in life or death situations with fierce opponents, his Haki continues to increase...
...to the point of counter-attacking and catching off guard, the future sighted Charlotte Katakuri during their duel.
Thanks to his rigorous training regimen, Roronoa Zoro (One Piece) has excellent reflexes as he can effortlessly dodge deadly strikes...
...block high-speed projectiles...
A very agile man, Sanji (One Piece) possesses an incredible amount of reflexes as he can easily dodge death blows...
...counter his annoying rival, Zoro's sword strikes during their one of their heated fights...
...dodge high caliber bullets at point-blank range...
...and thanks to his immense mastery of Kenbunshoku/Observation Haki, he can evade and dodge an attack from the likes of Charlotte Katakuri.
Due to her Mink rabbit heritage and training as a guardian, Carrot (One Piece) has fantastic reflexes as she effortlessly dodges Zoro's sword slash from the front...
...and while in her Sulong form, she can easily evade deadly strikes from powerful opponents like Charlotte Daifuku's Genie.
Makiko Oriotori (Horizon In The Middle of Nowhere) has such supernatural reflexes that not only can she avoid getting touched by every single person in class 3-Plum, but she can even dodge homing attacks as well.
Nicknamed the Yellow Flash during his lifetime, Minato Namikaze (Naruto) was infamous for his incredible reflexes while using the Flying Thunder God technique as he was able to dodge his rival Ay/A's lightning-powered attacks within in the blink of an eye.
Thanks to Sage Mode, Naruto Uzumaki (Naruto) reflexes are dramatically increased to the point he could dodge and redirect the legendary Third Raikage's Hell Stab technique.
Fourth Raikage Ay/A (Naruto) coating himself with electricity to drastically increase his reflexes.
Thanks to the immense mastery of the Sharingan, Madara Uchiha's (Naruto) possess spectacular reflexes as he easily dodges, evades, and counter the attacks from over a thousand ninjas at once.
Thanks to the power of the Eight Gates, Might Guy (Naruto) can dodge blows from Madara, even in his powered-up 10-Tails form.