I have a few that really bug me that will piss off everyone that reads this, but regardless.
First is Mikasa from Attack on Titan. She has all the character and personality of a brick, having one thing that happened to her and one personality trait that keeps her from being the ultimate Mary Sue, and that is her obsession with Eren because of the whole slaver deal. She kills a man at age 10 after her parents are killed and suddenly she loses all personality and yet is more athletic, intelligent, and just better at everything than every other character in the anime? No, that's where I draw the line. Her entire existence is 1/3 of the reason that I hate Attack on Titan, and yet everyone who watches the show talks about how cool and badass she is. I hate it when characters in any sort of narrative medium are written like this.
The second is Ellie from The Last of Us. Frankly, I never liked this game. I liked the gameplay, the graphics, voice acting, the soundtrack, and the atmosphere, but I couldn't get past how badly I saw each character was written. Joel was a stereotype, with his actions being able to be predicted a mile away, Tess was the biggest ***** I had ever seen in a fictional medium, Sam and Henry... what is there to say? But Ellie? Not a stereotype, mind you, but uninteresting nonetheless. The one thing that I liked about her was her joke book and she quit one third of the way through the game. After that, it was just the generic growth and proof that she could take care of herself that I had expected. What REALLY pisses me off, however, is how Naughty Dog handled her reveal to be gay, or at least bisexual. I hate this about this game. I hate it when someone comes out like this, like it's some big thing, when as far as I can tell, we are in an era that accepts gays as they are, and anyone who doesn't isn't listened to anyways. I don't know a single homophobe, nor have I ever met on, online or offline. When I find out that someone is gay, I don't care. I couldn't care less. Want to know why? Because it affects absolutely nothing at all. Coming out is the exact same thing as confessing to your parents that you are black. Do you know how annoying it is when someone reveals that they are gay? Why should I care? Will affect anything related to me or anything else? Will this prevent you from being a civilized person in society? No? Then why bother talking about it?! I don't care that Ellie is gay, and yet everyone can't seem to let it go! Why couldn't Naughty Dog have handled it like they did with Bill, where they just off-handedly mentioned it?! Why was it a big reveal?! It makes even less sense in their context because no one ever oppresses gay people in the game!
Sorry I went into a big rant, but I just needed to get this off of my chest.