This could be a game, franchise/series, genre, developer, or overall publishing company you refuse to purchase games from.
Me personally? I have never played a COD game nor do i ever intend to spend my money on buying one.
Dark Souls because unlike those who play it, I dont have much time and I also enjoy completing my games.
Gran Turismo. Even as an avid Playstation supporter, I cant get over how boring the series is compared to Forza, which I'd rather have.
I also have a personal distaste for anything Zombie related. Too many games. Same gameplay. Oversaturated. Closest one I enjoyed was The Last of Us. Where are the dinosaur games?