The Witcher 3 hurt other open-world games with its better side-quests and story.
Mark of the Ninja and Invisible Inc. hurt my enjoyment of other stealth games, by being more unique and fair than other big series like Hitman, Metal Gear Solid or Splinter Cell were providing me.
XCOM: Enemy Unknown & 2 kinda killed my desire to play Japanese tile-based SRPGs, because of how much more dynamic their approach was. Instead of flat levels with only tile count away, status effects, and minor bonuses on elevation they just don't do much with your environment. In XCOM you have half/full cover points, destructible terrain that opens up greater hit chance, planning out overwatch counters, more interesting abilities than just elemental effects, and 2 added in the concealment aspect. Stuff like FF: Tactics and Tactics Ogre just don't interest me anymore.
Bloodborne and Dragon's Dogma: Dark Arisen hurt other action/RPGs with melee combat, because they just did a better job. Both were fast in the way I liked, both have a good deal of weapon variety, and managed to make gear and numbers not hurt the experience.
Dishonored's level design and ways your abilities could be applied has spoiled me for most other 3d action games. The levels had so much thematic variation, continually refreshing multiple paths unlike Human Revolution's air vent fatigue, cool lore and side-events you just happen across for exploration, and supported a variety of ways to play with ease. Each ability in Dishonored felt worth 10 in other games for how many ways you could apply or combine it with others in a given level.
Middle-Earth: Shadow of Mordor spoiled me on bosses for other games. Instead of giant hulking monsters or mysterious figures I barely knew anything about or had much connection with, the game instead had them build up over time as nemesis. Sometimes they'd come out of nowhere, and make my day so bad I had to retreat, or I couldn't get them before they bolted. It gave me a personal connection to bosses, except for that final one...that was a dumb QTE.
Gears of War 3 has hurt every other third-person cover based shooter I've ever played since. I can still enjoy them enough, but in the back of my mind they're being compared to Gears 3, and always found wanting. I've pinpointed 5 main attributes as to Gears 3 is better: the controls and feedback on weapons just feel perfect, there is actual weapon variety there beyond standard-ass guns, the enemy variety is just better/more interesting than most other games period, the sound design makes those enemies actually memorable enough to bother learning their names, and that weapon/enemy variety on higher difficulty pushes you to constantly be moving through cover vs. turtling.