Games that are so good they've ruined every other game in their genre for you

[OneCatch]

Two for me:

Company of Heroes kind of ruined the 2.5D highspeed RTS for me - it's not as specialised or deep as others, but the gameplay was fantastic. CoH2 I couldn't get along with for some reason, think it's because the Russian faction was really micro-ish.

Alien: Isolation for survival horror. Perfectly recreated the world of Alien, and managed to combine unarmed/unforgiving/evasion gameplay with limited combat/elimination/stealth elements.

 

[KyuubiNoKitsune-Hime]

I don't have much at the moment, but... Shovel Knight has ruined me for other 2D side scrollers. It's controller snapping frustration done just the right way. Also the cheat X&BUTT Butt mode. The line to King Knight from Shovel Knight: "Prepare for justice! Butt justice!" That made me laugh harder than any video game ever has any right to.

 

[Elel]

FPS - Deus Ex, the old original one. I literally stopped playing FPS games after playing it, because I realized how limited they are! Right now it's not such an issue, but back then FPS games were about shooting only: no talking, no characters of interest, no choices. I'm not kidding, because of Deus Ex (along with its sequel Invisible War) I haven't played FPS games for years! Until Deus Ex: HR came out and I was lured out of isolation by a title that produced an impact before.

CHARACTERS - Dragon Age series, especially Inquisition. It's not a genre, but it matters, because in no other games characters were as "alive" and realistic, and so they now feel very shallow, like carbon half-thought-out stereotypes. I get continuously disappointed with characters in all games I'm playing.

VISUAL NOVELS - Higurashi, Umineko. It helps that pretty much all other VNs are cheap crap, like eroge.

DETECTIVE - Danganronpa. Seriously, I'm not saying all other games are bad or that I'm not playing them, but they're not like that. Detective games tend to have a very mellow pace and can hardly ever elicit excitement. This one is anything but that.

 

[Arkliem]

Space Sims: The X series, specifically X3: Reunion (I know it isn't as good as Terran Conflict, but I like it better dame it!). I can't put it into words, but until Rebirth ruined it all it as without a doubt the greatest space sim series ever made.

Good choice. Very good choice. I'm a TC guy myself, but Reunion and TC are fairly close. But those resource requirements for the hub o_o. Yeah haven't seen any space sims that can match it yet. Quite the bummer the direction they took with Reunion.

For 2D based space adventures...Star Control II(Or Ur-Quan Masters). Mass Effect basically took SC2's plot and squandered it.(The reapers are very analogous to the Kohr-Ah [https://www.youtube.com/watch?v=pjJOu-VyDY8], with slightly different motivations.) Aliens are all quite diverse instead of being mostly human-like. The Mycon [https://www.youtube.com/watch?v=N3OB7Kjfm0A] and Orz [https://www.youtube.com/watch?v=gIbVYXHnaBU] being extremely bizarre. The former seems more hostile, but as you come to know the latter you realize they are much more sinister.


Don't really know if there are any others that have ruined every other in the genre though for me.