Bowser, from Nintendo's Super Mario franchise.
Bowser is without a doubt the king of video game villains, with his iconic reoccurring appearances in the multitude of Mario games always delighting fans and critics alike. He is universally recognised throughout the pop culture world and even the most tame of gaming fans will know his name. Bowser is relentless in his efforts to cause Mario, Luigi and co. havoc, being truly evil for no other reason than because he is powerful and he enjoys it, fitting the classic villain trope and earning him a spot on the list.
Doctor Eggman, from Sega's Sonic the Hedgehog series.
A rival to Bowser for the video game villain throne, Doctor Ivo "Eggman" Robotnik is a cunning genius with an IQ of over 300, who plans to take over the world and establish his own empire. Eggman is relentless in his plans for world domination and devises countless plans involving a multitude of different technologies, magic and other strategies. Sonic and his friends always manage to defeat Robotnik but he somehow consistently evades capture and is an escape artists for the ages, continuing the age old feud between him and the blue hedgehog forevermore, earning himself a spot on this list.
Ganondorf, from Nintendo's The Legend of Zelda series.
A villain of pure evil and cruelty, Ganondorf is the main antagonist of the series and Link & Zelda's arch nemesis. A warlock whose main ambition is to usurp the kingdom of Hyrule for himself and gain the power of the Triforce, he is a mastermind who doesn't let his lust for power cloud his judgment and remains committed to his goals. He is said to have little to no morality despite presenting himself as a calm and civil man, being short tempered and murderous underneath the surface. He is a skilled swordsman, astute wizard and a cold hearted villain, earning him his spot on the list.
Gary Smith, from Rockstar Games' Bully.
Gary is a main character and the main antagonist of the cult classic game Bully. Gary is said by numerous characters in the game to possess many psychiatric disorders such as narcissism and antisocial personality disorder as well as a sprinkle of paranoia and delusions. During the Halloween missions, Gary can be seen donning a Nazi Officer uniform; further emphasizing his mental health issues and how he views himself. Throughout the game he manipulates several characters, including the main character Jimmy, and destroys relationships in the process. His cunningness and irreverent personality as the main antagonist and a complex character in an all round amazing game earns him his spot on this list.
The Joker, from Rocksteady Studios' Batman: Arkham series.
One of the most terrifying portrayals of the clown prince of crime, topped off by a chilling performance by Mark Hamill and a harrowing character design, Arkham's Joker is truly the pinnacle of the character. The Joker is without a doubt Batman's arch nemesis in the franchise, with his ultimate goal for the caped crusader being to make him take a life. The Joker is responsible for some of the darkest occurrences in the series; he is to blame for the paralysis of Barbara Gordon, the abduction, torture and murder of Jason Todd a.k.a. Robin, and the death of Talia al Ghul to name a few, earning a spot on this list.
Vaas Montenegro, from Ubisoft's Far Cry 3.
Vaas is a textbook villain, betraying his people for his own personal gain and antagonizing the main character Jason Brody throughout Far Cry 3. He is notorious in the gaming community for his "Insanity Monologue", a cutscene from the game which has become iconic across gaming and meme culture since its release. Ubisoft were said to have written and designed his character to be a Darth Vader level menace, someone who was so far off the deep end and would hold no remorse for his actions, becoming an action gaming icon and being regarded as one of the best written villains in video game history.
Monokuma, from Kazutaka Kodaka and Spike Chunsoft's Danganronpa series.
Monokuma is a chaotic and peculiar villain with a quirky and short tempered personality. The main angle Monokuma takes is placing high school kids against each other in a detective style killing game where the students must try and get away with killing one of their friends in order to survive, or they will be trapped forever in Monokuma's game; the titular bear provides plenty of motives to each of the students to push them over the edge. Students caught out by the other students during the class trials are subject to extreme and humiliating executions. He takes on the appearance of a bipolar stuffed bear, but Monokuma is something far more sinister. His exact goals are unclear and he only has one real motive: to cause absolute chaos and anarchy, earning him a spot within the best video game villains of all time.
GLaDOS, from Valve's Portal series.
GLaDOS is an artificial intelligence program comprised of a human being's conscience who oversees the Enrichment Facility where Portal and Portal 2 take place. She is ruthlessly violent and is said to have tried killing the scientists that created her within one tenth of a picosecond after being activated. She is said to have been fitted with a morality core in order to curb her murderous intent and pursue scientific advancement instead, but her need to create the portal technology resulted in the sacrifice of many human lives in the process. She constantly terrorises Chell with her immense intelligence and cold machine logic throughout both games. As the fear of AI in society is more prevalent today than ever, GLaDOS is a stark reminder of what can go wrong and remains relevant even 17 years after she first graced her way onto gamer's screens, earning her a spot on within this list.
I hope you've enjoyed this little compilation and if there's any you think I have missed, please let me know in the comments below!