I don’t have near the experience playing these games as many in the community, so take this list with large boulders of rock salt. Here are the games that challenged and changed the way I think about IF and the realm of possibilities open to IF Works (in no particular order):
-Counterfeit Monkey
-Cragne Manor
-80 Days
-Haden Lands
-Eat Me
-The Wizard Sniffer
-Junior Arithmancer
-The Wand
-Open Sorcery
-my father’s long, long legs
-Creatures Such As We
-Sorcery! series
-Animalia
-Harmonia
-Bandersnatch
I could probably easily make a second list at least as big of games I heard were really good (e.g. Taco Fiction, Howling Dogs, Cactus Blue Motel, Choice of Robots, Heaven’s Vault, etc.) and I just have not had the time to experience yet. In other words, a year from now, this list will be a lot bigger. But this is what I know now ;).