Whats your favourite game thats beenruined by hacks

For me It was WOTLK private server 'Eternal'. Lately most hackers and ninjas are ruinning the server. Before the population was around 500 people but now only a single digit most of the time.

Rainbow Six Siege here, though Ubisoft is now finally gettng a firm stand against cheaters and boosted players.

GTA 5 online was utterly ruined by modders. The single player was/is amazing but online was a huge disappointment.