Honestly not sure what game I think shouldn't have existed, even the bad ones taught lessons about what I did and didn't like saving me from other bad games, moreover teaching the industry with each failure.
Though part of me wants to say Call of Duty as I've slowly grown a dislike for them, they are all loved and played by millions, moreover COD 4 was a great game and deserves life damnit!
Another part of me wants to say Half Life based soley on that small minority who go batshit insane everytime someone suggests it might not be the best thing in the history of gamerkind and hate anything considered by people to be superior, for example on these forums I've seen threads on 'OMGZ HOW Teh hell iz Mass Effect, Halo, COD, GTA, Battlefield better than halflife?!?!?!111oneoneone'. Yes it's a great game, but that small (small) minority of people really do piss me off. But again, Half life deserves existence as it's a great game and hell if I'm going to get pissy about a community I'd have to detonate everything popular and we'd all become hipsters and seriously fuck that idea.
Screw it, destroy the newest Prince of Persia game. I'd rather it never have existed than have to feel dirty for liking that game.