5. Frank Fontaine (Bioshock)
Throughout the majority of the game, Andrew Ryan is the primary antagonist and Atlas is the helpful guide, giving you advice via radio. Then the mid-game twist happens, one of the best twists in video game history, and you learn nothing is what it seems. It turns out that Atlas is in fact Frank Fontaine, and he has been manipulating you the entire game. Many times in game characters betray one another and plot turns make allies become enemies, but rarely is a game capable of making you, the player, feel betrayed the way Bioshock does. The only character that helps you turns out to be the evil man behind the curtain pulling all the strings, and it really makes you want to kill him.
4. Kefka (Final Fantasy VI)
Kefka is the main antagonist for the entirety of the game, and he is quite simply insane. The insanity is really what makes the character work. Kefka is a mad jester, with one of the most terrifying sound cues (the laughter) that the Super Nintendo has ever produced. Add to that the frighteningly appropriate music and you’ve got the most iconic and memorable of the Final Fantasy canon.
3. Bowser (Super Mario)
Originally known as King Koopa, Bowser is pretty much the definition of a classic video game villain. Pretty much everybody knows who Bowser is, and he has appeared in a huge amount of games. He may not always be the villain, sometimes opting to play golf, board games, or race go-karts; but he is the villain in the majority of the game. He is certainly not the menacing or devious of the villains on this list, but he makes such a high spot simply because of his long history and status as a gaming icon.
2. Ganondorf/Ganon (The Legend of Zelda)
Compared to Bowser, Ganon is neither as old or well known, but he makes up for it in the department of actually being a villain you can take seriously. Of course, like most villains, he is usually defeated by the hero, but Ganon has a much better track record than likes of Robotnik and Bowser. Ganon actually tends to be a real threat, and the whole immortality thing is also fairly threatening. In games set hundreds or thousands of years apart, Ganon always seems to be alive, doomed to fight and lose to the ancestors of Link and Zelda.
1. GLaDOS (Portal)
GLaDOS is at times the comic relief, and at other times the antagonist, while at others she’s a sidekick, and more often than not, she is two of these or even all three at once. The reason GLaDOS makes number 1 on this list is quite simple; the writing. She is one of the funniest characters ever seen in a game, and also one of the most intimidating. She spends a lot of time trying to kill the player characters, but most of that time is quite funny. If it is possible to like a character that is constantly trying to kill you, GLaDOS is that character.