this thread has reminded me that my single best and worst gaming experiences were with the same game, 'wraith: the oblivion,' and how each was as good/bad as it was because of the rules, themselves, more than just the players.
i've got one big box full of 'pathfinder' 2e and another big box of 'starfinder' stuff and i'll never play either one (and will hopefully be getting rid of them, soon.)
that being said! i have a number of games that i will probably never play again but i like them enough to keep them (and...
the two i most enjoy are those found in 'dungeon crawl classics' and 'ars magica' (which, funny enough, feel incredibly oppositeional to each other in some ways while being very sort of philosophically aligned.)
it's been my go to rules system for horror games of all sorts for decades, now, and i haven't used anything from the 'mythos' in most of that time (and we just switch 'sanity' for whatever is most setting appropriate.)