El Goonish Shive: Camdin thinks he and his friends were selected to be heroes. In truth, Pandora marked them as part of her overall master plan to break the masquerade on magic, and she considers them delusional.
Erfworld has Stanley The Tool, who is convinced that he's destined to collect all of the Arkentools, despite the fact that he's a bungler with no concept of strategic warfare, diplomacy, or logistics. He did seem like he was going to be brought down a peg when Wanda became attuned and wound up getting more amazing powers than him, but alas, it was not to be! The damnable thing is that he DOES know what to do in an actual fight as long as he's the one fighting, and earned his way from mook footsoldier to Chief Warlord on those merits. It's just that those merits weren't strategy, diplomacy, or logistics.
Exterminatus Now has this in the form of Rogue, who, being the only member of his four-man team who isn't idiotic, ax-crazy, or downright repulsive, tends to act in a "better than you" attitude, despite not being that much better than his compatriots.
Sam Starfall from Freefall is an example, of a sort. He always plays the big guy (even going so far as to attempt to introduce himself as an ambassador to the "puny human empire" despite humans being more advanced than his species). The difference is mainly in his goal (to become a famous thief or criminal) rather than his mindset - though Sam does seem aware that he isn't famous yet.
Guilded Age The bard in this series, Payet Best, becomes this after he visits a small town and gets hailed as a hero. Lampshaded with the Achievement Unlock: Become a huge Douche.
Eridan Ampora is an arrogant snob who feels entitled to love and reverence, yet most of his peers view him with opinions ranging from pity (platonic, of course) to outright loathing.
Cronus, if anything, is even worse. He's totally convinced that he is a sensitive, artistic soul who is a musical genius and an all-around selflessly nice guy. In reality, it's perfectly plain to everyone that the entire thing is just an act to convince people to sleep with him. While Eridan did actually have a good friend in Feferi even after they stopped being moirails, Cronus is disliked by literally every single other character who has ever come across him. Ouch.
Sluggy Freelance's Sam, being a vampire, is way stronger and faster than most of the cast, survives a fight with a major demon, and is a Jerk with a Heart of Gold. Unfortunately for him, the only thing he cares about is having sex with as many women as possible, which he is awe-inspiringly terrible at, to the point that his normally extremely potent vampire hypnotism is entirely ineffectual.
Stand Still, Stay Silent: Due to growing up as a pampered rich kid before hitting a Riches to Rags episode, Emil grew up thinking he excelled at all his chosen subjects, only to have his grades drop the second he entered the public education system. He however interprets this as the school system having it in for him and hopes to prove himself in the army to show the world that he actually is as good as he thinks he is. When it comes to his army job, he does have some talent, but lacks experience (he joined later than most due to initially having a long schooling period by that world's standards) and, most likely given the above, the right attitude to go up the ranks.
Starslip's Memnon Vanderbeam: He is good at his trained profession (Art expert) - just not as good as he thinks he is. And he thinks that expertise transfers to his current job (Starship captain/cultural ambassador). His arrogance and intellectual snobbery don't help. He develops out of this as the comic goes on- a war games incident where things unexpectedly went hot showed him to be a fairly competent tactician in the heat of battle, and the comic's ending gives him a much bigger name as he successfully halts human evolution and re-writes the future.
Phillip Kim acts like his name is one to remember but, as Ben points out, being a graduate of Imdo Middle School doesn't mean much. Most of his power and influence comes from him bribing others; strip that away from him, and he's pretty pathetic.
As soon as he forms a connection with Helmet (who's barely more than a Mook for Jimmy's gang) Hugo Yoon's ego inflates tenfold and he starts bragging about his greatness to anyone who will listen. He even claims he could take Gray in a fight.
Hayden is one of many who's confident he can take Gray in a fight, even after being told that Gray was the one responsible for taking down his Ax-Crazy boss Wolf. When they finally square up, Gray doesn't even break a sweat when wiping the floor with Hayden.
