There’s a mod which restores content cut from the Brotherhood’s storyline, allowing the player to not only kill Maxson but also bring Danse back into the fold.
I think I was unclear: I wanted to kill Micah for the longest time.
How about Kuja from Final Fantasy IX?
You can kill Maxson in the unmodded game just fine, although not without trashing your reputation with the Brotherhood in general. If you end up siding with the Institute or the Railroad, you’re required to kill him to beat the game.
Handsome Jack and GlaDOS are definitely my picks. It’s the amount of energy they put into being assholes that makes them top contenders: in addtion to their grand plans for domination or power or whatever, they obviously just spend a lot of time thinknig of things they can say that are gonna ruin your day. GLaDOS’s constant gaslighting puts her a little ahead, in my book.
Fuckin cake.
Maybe. Isn’t there an implication that Johnson forced his assistant to become GlaDOS against her consent?
There is, but she’s still a grade-a schmuck in Portal 1, and even after her backstory, she doesn’t exactly end up as a hero in Portal 2.
I do not think the Portal 2 backstory was so much that Johnson forced his assistant to “become” GlaDOS, but that he uploaded her to GlaDOS as an unwilling guinea pig in a typical Caimh Johnson experiment (eventually he intended to upload himself), and that was a key contribution to making an already-unstable GlaDOS that much more psycho crazy. GlaDOS is eventually able to delete the file, however 
The lines used in the game were:
Brain Mapping. Artificial Intelligence. We should have been working on it thirty years ago. I will say this - and I’m gonna say it on tape so everybody hears it a hundred times a day: If I die before you people can pour me into a computer, I want Caroline to run this place.
Now she’ll argue. She’ll say she can’t. She’s modest like that. But you make her.
Hell, put her in my computer. I don’t care.
But there were also several unused voice files in the game where Caroline says things like “Mr Johnson, I do not want this!”
That mod, unfortunately doesn’t play out quite the same way the cut quest it’s supposed to be restoring. The Sole Survivor ends up as the new Elder, not Danse. Which would be OK…except the used dialogue from the originally intended version where they don’t actually treat you like the Elder.
Still enjoyed shutting the little bigot up. (And he was such a nice kid in 3…Sort of the opposite of MacReady… Kid’s still kind of a pill at times, but nowhere near the little asshole he was as a brat.)
I dunno, I think I’d give it to Jack.
GlaDOS is an asshole to Chell (and presumably her other test subjects) while she has her in her clutches… (And when they’re forced to work together to get rid of Wheatley…) But once she gets out, she’s just glad to see the back of her.
But Jack goes out of his way to be a pain in the Vault Hunters’ collective ass, calling them out of the blue, tracking their location in order to be a location-appropriate pain in the ass…creating the frigging Morningstar, for Satan’s sake!
I never found GlaDOS particularly hateable. She’s certainly trying to be an asshole, and the whole “trap you in a scientific facility and do insane experiments on you 'til you die” is definitely evil, but her attempts to insult and gaslight you are all so hilariously inept, I can’t really get angry at her, the way I can at Handsome Jack or (spits) Ted Faro. Take the whole cake thing, for example. A villain forcing the hero to jump through hoops by dangling some reward in front of them, only to renege of the deal when the job is done, is prime asshole behavior. Except in this case, the reward was something I didn’t (and wasn’t supposed to) care about, so the whole, “Ha ha I was lying about there being cake,” doesn’t have any burn to it at all. Or calling the protagonist “fat,” when you can see the character’s model and she is, in fact, extremely fit. GlaDOS wants to be cruelly manipulative, but doesn’t understand humans well enough to actually pull it off, and it just comes across as charmingly clueless - so long as you ignore all the gun turrets.
And the neurotoxin.
I think what happened with GLaDOS is that some poor technician gave her a figurative answer to a literal question. She was programmed right from the start that her purpose was to advance science. So naturally, she asked, “What is science?”. And the answer, unfortunately, was something like “Science is how humans confront adversity and keep ourselves alive in a hostile world”. So she creates adversity and a hostile world for humans to confront and try to stay alive in.
And I’ve got a new nomination. In City of Villains, the evil side of City of Heroes, a lot of the missions are the same kind of thing as in the good side, saving the world (so you can rule it), or defeating villains (because they’re competition), or the like. And players complained that it wasn’t evil enough. So the developers added Weston Phipps. He ostensibly runs a refuge house in the crime-ridden Rogue Isles, but it’s actually just a ploy to set up his “guests” for even greater heartbreak once they think they’re safe. His main mission arc is all about crushing the operations of an altruistic and surprisingly successful schoolteacher, just because she’s bringing hope to people.
And all of the players who asked for more evil promptly said “No, not like that!”.
nevermind…
And the missiles.
Okay, yes, and the flamethrowers.
Look, I’m not saying she’s nice…
No love for Wreck-it Ralph?
Huh.
Aw. c’mon. Ralph’s a bad guy, but he’s not a bad guy.
Is Calypso from Twisted Metal disqualified? He’s a massive asshole who screws the winner of his demolition derbies in the most trolling ways possible. He’s been granted powers by Satan, so “evil” is certainly in operation here. But he doesn’t want to take over the world, he seems to just want to watch it burn, one driver at a time.