Dr. Weil, the utterly despicable Big Bad of the Mega Man Zero series. It all started with how he, and he alone, thinks humans deserve to rule the Reploids, and single-handedly triggered the Elf Wars. Later, he is given a Fate Worse Than Death that is technically escapable. Then he starts taking over the world, and making people suffer just because they all made him suffer. As Weil puts it:
Dr. Weil: Justice!? Freedom!? Worthless ideals! You Reploids are just machines, but you started a war a long time ago in the name of freedom! And humans! Look what they did to me! Driving me away while spouting the word "justice!" Zero, would you insist on saving them!? Controlling the Reploids is nothing! The destruction of all mankind is only fleeting!
Similarly, the villains from the Mario & Luigi series, the first and third games in particular. Cackletta starts out more or less like any normal villain, but turns into this roughly when she takes over Bowser's body to become Bowletta. Fawful is already in this in the first game (he has a literal camera crew with spot lights and speech before his boss battle), but by the time of Bowser's Inside Story, has gone straight off the deep end, with his face on every object in sight (statues, floors, trains) and the entirety of Bowser's minions treating him as a celebrity under mind control.
Final Fantasy IX has Kuja, who robs the whole bakery. The motivation for his Suicidal Cosmic Temper Tantrum: He was informed that he was mortal and thus would die soon, and he found it utterly unfair that the rest of the universe was allowed go on existing without him. Naturally, something had to be done to correct this grave injustice.
Aire in Final Fantasy: The 4 Heroes of Light is completely self-centered and only cares about her style and comfort to the point that Jusqua ditches her. She gets a huge wake-up call after her greed gets her cursed into being a cat and her fairy companion, Lilibelle, does a Heroic Sacrifice for her.
God of War, has Kratos, a man who killed a pantheon rather than admit that maybe, just maybe, something was his own damn fault. Most evident in the second game, when he starts doing the exact same thing that Ares did, i.e. the thing that prompted the gods to help Kratos kill him. Then he claims that the Gods of Olympus betrayed him by stopping him. This gets called out in the third game, where Hermes gives him a Breaking Speech on how his path only leads to destruction and Kratos undergoes a slow Heel Realization. Also lampshaded in the first game, where it's shown in a flashback that his wife Lysandra refused to believe that his brutality was for "the glory of Sparta" as he claims, telling him that he does it all for his own personal glory.
Mori Motonari from Sengoku Basara. What we have here is a guy who calls himself "Child Of The Sun", commands a battalion of devoted soldiers...that he considers disposable pawns, and will kill when it's beneficial to him, then takes all the glory for himself (to be fair, he does come up with 100% of the strategies). His goal is to Take Over Japan. And while others have pretty righteous reasons for doing this, Motonari does it for himself only.
It is taken Up to Eleven with Zanza from Xenoblade, the local Jerkass God who is utterly incapable of acknowledging the value of anything that isn't himself, and is constantly using his power to destroy and rebuild the universe because fuck you. Also because of the fact that if his creations leave him, he'll die, but that doesn't excuse him for being such a massive dick about it.
Arl Howe from Dragon Age: Origins, who was also The Resenter. He betrayed his best friend, Bryce Cousland, and slaughtered most of his family before throwing his lot in with Teryn Loghain. When questioned about this later by a human noble PC, he has the audacity to claim that Bryce was a traitor because he made frequent trips to Orlais. Throughout the conversation, however, he reveals that he was simply resentful of the Couslands' success. As shown in the Awakenings expansion, Arl Howe's actions end up bringing shame to his family and his children end up as pariahs. Even his Famous Last Words are an example of this trope.
Maker spit on you … I deserved more …
And Marjolaine too. Marjolaine betrayed her disciple and lover under the belief that Leliana would EVENTUALLY betray her, and then tried to sell out her own country to Harwen Raleigh.
When you meet her in the main game, she still thinks it's all about her. If you try to tell her that Leliana has moved past her betrayal to help fight the Blight she angrily dismisses you and insists otherwise. Marjolaine actually believes she is more important than the freaking Darkspawn.
Tales of the Abyss main character Luke starts out this way. Anything that does not involve either himself or Master Van is boring and unworthy of his attention. A large part of the story focuses on his transition from a self-centered, spoiled brat into a self-sacrificing hero.
Tales Of Destiny 2 has Barbatos Goetia, who ended up being written out of history for his utter lack of sympathy towards both his comrades and enemies, using the former as tools to gain more glory for himself. When he's revived by the Big Bad, he's perfectly willing to travel through time for the purpose of killing the heroes of the first game on the promise that he'd be made into a hero if he did. He maintains this mentality to the very end, where he opts to commit suicide rather then be defeated by the party, on the basis that he views himself as the only one worthy of taking his life.
Prince Laharl from Disgaea: Hour of Darkness is, by his vassals' accounts, a self-centered brat with a massive entitlement complex. For example, he didn't expect to actually pay his vassals, since he'd have to share his allowance. He eventually shapes up (a little) when he realizes that they won't work for or respect him otherwise.
His vassal Etna is not above it either. She's perfectly willing to send her minions on suicide missions to satisfy her Sweet Tooth, and barely pays them anything. In the second game, she joins the party after an incident where she screws them over by giving them a fake ingredient For the Evulz. This backfires when their ritual inadvertently causes her power to vanish, then she proceeds to demand they fix her problems for her despite being the one at fault. However, she later opens up to Hanako after she shows interest in her, and eventually takes in and trains her to become a Future Badass Demon Lord after the two grow closer together.
After the sheltered princess Rozalin is accidentally summoned, she initially does this when she demands Adell focus entirely on her needs. She gets over it over the course of the story after befriending Adell's siblings, seeing the effects of her father's curse on the world, and being touched by Adell's commitment to his promise.
Walnut from Phantom Brave. His entire strategy as a Chroma Oxide is to cheat other Chromas and steal their payments, and repeatedly supports his view with claims about "money rules the world" and "only the strongest survive", yet feels severely mistreated when the people he cheated, who are usually stronger than him since they tackle the things he won't, punish him for it. He develops a very one-sided rivalry against Marona because she defeats him, because she's making progress without having to stoop to his level, and because she befriends his ill sister Castile, making her genuinely happy (while he left to get money for her medical bills, thus making her lonely). Eventually his attempt to ambush Marona on the Island of Evil leads to the release of the Big Bad, Sulphur. (Admittedly no one had any idea that would happen.)
Pokemon Black And White: The first hint that Ghetsis's motives may not be wholesome is when he slips up in a speech at Castelia City. He is quick to correct himself, but for the observant, the damage has already been done.
Jon Irenicus from Baldur's Gate2 to a horrifying degree. He was like this even before his soul was stripped away. Irenicus endangered the lives of his entire race by trying to siphon the power of the Tree of Life in his bid for godhood; an act so heinous and sacrilegious that the Elven Queen Ellisime (who was his lover at the time) tore away his immortal elven soul and banished him with the Elven gods' blessings. Irenicus considers them monsters for taking away his soul and doesn't even acknowledge that maybe he had it coming what with nearly killing his own species. It gets worse when the lack of a soul caused him to develop a Lack of Empathy as well. Irenicus doesn't see people as people anymore after that point. To him, they are just tools to be exploited, slaves to be worked to death, experimental subjects, or targets for revenge.
He needed some prodding by his much more empathy-lacking sister Bodhi before he started this kind of mindset.
Rift: Prince Hylas comes to mind as while this isn't necessarily the primary motivation for the rest of House Aelfwar departing to join up and work with Greenscale's life plane, it certainly is for him. When his lover left for war and returned as one of the Ascended, he spurned her for no other real reason than that he and the other High Elves were no longer the Vigil's favourite.
What Andrew Ryan says of himself through the creation of his underwater capitalist paradise Rapture in the firsttwo games. He even believes that it is the nature of all humankind to think this way, telling the protagonist "In the end, all that matters to you is you, and all that matters to me is me.".
Alex of Golden Sun. When you encounter him in The Lost Age after adding Piers to your party, he's quite offended that you found a new Water Adept who actually cares about your mission enough to, you know, tag along and help you himself... and then he reveals his hypocrisy by introducing you to his new allies. And then he double-crosseseverybody, including Karst and Agatio. Lampshaded mercilessly by Jenna and Sheba after just about every cutscene featuring Alex.
James Tobin from ''In the 1st Degree. Yvonne Barnes states that Tobin is completely full of himself, and that he ended up blaming his business partner Zack for all his problems. Interestingly, it is stated that he slept around, and that he was likely cheating on his girlfriend Ruby. However, the minute he finds out that Zack and Ruby had a one-night stand, he flies into a terrible rage and decides that he has to murder Zack. Yes, he thinks it's okay for him to cheat, but it's not okay for his girlfriend to cheat. What you have here is a man who lives and breathes this trope.
In World of Warcraft Garrosh demonstrates this sometimes. Baine Bloodhoof calls him out on the fact that his chief concern over killing Baine's father appears to be that he lost honor by doing it with a weapon he didn't know was poisoned.
While true, this isn't one of the best examples for Garrosh. Cairne Bloodhoof is the one that first suggested the duel, while Garrosh suggested it be to the death. Cairne knew damn well what he was getting into, and Garrosh is honestly shamed by the fact that he only won the fight because his weapon was poisoned without his knowledge or consent. His attitude here is less self-centered and more unable to understand that Baine holds any real resentment over a very public affair that was very much Cairne's own choice (albeit in large part because Garrosh became an Unwitting Pawn to Magatha by creating the opportunity she needed to take over Thunder Bluff, to the point at which Baine was unsure whether Garrosh was knowingly working with Magatha). There was always the chance that Cairne wouldn't be the winner right from the start.
While the duel mentioned above may be YMMV, the trope hits Garrosh real hard in Mists of Pandaria. His notion of the "True Horde" (orcs who agree with his vision) and persecution of all other Horde members who disagree is this and more.
Garrosh also believes that the Orcs should march in and claim the fertile land of Ashenvale from the Night Elves, in spite of Thrall's belief that surviving off the barren land of Durotar was an act of atonement that would make the Orcs stronger as a people, and during the showdown with him in Siege of Orgrimmar, he expresses his belief that the Orcs deserve all of Azeroth, and their allying with the races of Azeroth was proof of weakness.
The Boss (player character) after he stops being a mute from Saints Row2 onwards is so much full of himself (or herself) that they cheerfully murder anyone who so much as suggests they might have become corrupt and have not even the slightest compunction about sacrificing others to save themselves. They either finally start to grow out of it in Saints Row 3, or shed all their redeeming qualities and become thoroughly corrupt, depending on the ending.
In Dwarf Fortress, the two most popular topics for necromancers to write about seem to be themselves and literary criticism of the books they wrote about themselves.
Demons who masquerade as gods to lead civilizations write very prolifically on their histories and philosophies, and how they're pulling the wool over the eyes of these stupid mortals. And they leave these strewn about their fortresses as if to mock everyone with any literacy.
Handsome Jack, the Big Bad of Borderlands 2, is so full of himself that despite his numerous atrocities and enjoyment of them, he thinks he's the good guy. The first time he claims this to the player(s) is followed by an anecdote about how he once carved a man's eyes out with a spoon in front of his family, the memory of which causes him to burst into laughter.
In City of Heroes, flame-wielding "hero" Flambeaux embodies this trope, to the point that when neither her team mates nor the public give her the love and attention she deserves, she undergoes a Face-Heel Turn. Her subsequent acts of (usually petty) villainy include trying to bomb a tabloid's offices for saying mean things about her.
Several characters in the Ace Attorney series, including Redd White, Richard Wellington, and Dahlia Hawthorne.
This is the defining feature of Draven in League of Legends. He joined the League because he wasn't getting enough attention as an executioner, his dialogue all boils down to "look at me!", and his ability kit reflects this. He's a Carry, which means he will be the cornerstone of your team's strategy. His passive gives him bonus gold whenever he secures a kill (not an assist- Draven takes the glory for himself), his main weapons are throwing axes that bounce off of his enemies and he catches, and his ultimate is a global skillshot that returns back to him, enabling several improbable and flashy kills.
While most Mass Effect villains ultimately have some kind of positive goal that they're going about in a terrible way, Henry Lawson - Miranda's father - doesn't seem to care about anything other than his "legacy" - i.e. his genetically perfected clones, who he treats kind of like shit, forcing them to meet impossible expectations, then disposing of them when they fail to live up to those expectations. Abusive Parents ain't got nothing on Henry. This isn't even going into his atrocities with Sanctuary. Whereas the Illusive Man does show at the end how much he does care about securing humanity's future, Mr. Lawson's primary concern is with how he'll be remembered by future generations. Watching him get thrown through a window is actually kind of cheering.
In Sword of the Stars, the Suul'ka enslaved their entire race to cheat death. After they accomplished this, they spent their immortal existences lording it over the other races. The oldest Suul'ka takes it even further by wanting to be the only living thing in the universe.
The world of Fate/stay night and everyone in it belongs to Gilgamesh. He'll kill anyone he thinks needs killing. He'll allow a self-admittedly evil man to kidnap, betray, and murder, because the victims were worthless scum anyway. But if someone goes around the city killing its citizens without his permission, well, that's a disgusting crime. Oh, Gilgamesh also eats the souls of forsaken orphans for magic energy, thinks that a little genocide would improve what he sees as a global overpopulation problem, and brutalizes, humiliates, and would-have-raped Lawful GoodLady of War Saber in a grotesque parody of courtship. In short, the "Good" part of his Word of GodChaotic Good alignment is practically impossible to swallow.
This expands to the level that not only the good, but the bad, is his. In Fate/Zero, Gilgamesh stares down and escapesthe inside of the Grail because all the world's sins and evils are his burdens to bear, and not the Grail's/Avenger's — after all, if everything in the world is his, then everything is.
His motivation to win the Fourth Holy Grail War was just nobody let winning the Holy Grail because he thought it belonged to him. When Iskandar asked him if he would recognize the Grail, Gilgamesh just answered he could not because his treasury is so big, he can't remember all of the treasures. But he claimed every treasure of the world is his.
He doesn't amuse himself only with evil, however. He's also de-aged himself to play soccer with a bunch of kids who needed an extra teammate. He might be too bad to be Neutral, but even Evil, he's not pure evil.
This also applies to Lord El-Melloi of Fate/zero. He fully expects the world to be handed to him on a platter and everything to always go his way. When Kiritsugu is battling him, he is naturally going to be the winner, because he's a prodigy! Things don't go well for him at all. But the whole time he's losing, he doesn't even realize it, because for him, the world works by giving him stuff and letting him always triumph. This also taints all his relationships, to the degree that he cannot understand his Servant's (entirely selfless) agenda and think he's hiding something because he thinks everyone else thinks like he does, and believes his fiancée loves him even though she despises him and their Arranged Marriage. In the end, Kayneth's one and only selfless act — sacrificing his Servant and bowing out of the Grail War to save his fiancée's life — leads directly to his death as Kiritsugu has both of them shot immediately afterwards.