r8 revolver
The R8 Revolver was, at one point, the most overpowered weapon in the game Counter-Strike: Global Offensive (CSGO) and was essentially a pocket AWP. For those of you who don't play CSGO, the AWP is a staggeringly powerful sniper rifle that can normally kill in one shot, as long as it hits above the legs. It also costs a lot of in-game money (4250 dollars) which would normally take at least three in-game rounds to gather. The R8 was a version of that which could not only be carried as a sidearm, but was also a paltry $850. The R8 was in fact better than the AWP, as it had perfect running accuracy, excellent armor penetration and a secondary rapid-fire option. The weapon was so overpowered, that the creators of the game, Valve, who are famous for doing things very slowly, took a mere two days to nerf the weapon, making it a total piece of shit.
Thank god they nerfed the R8 Revolver.