https://my9games.net
most of these i feel like are pretty obvious, but the two weird ones are osrs and myst.

osrs is a game i have tried going back to many times but i just can't do it anymore. i played it a SHIT ton as a kid though. it was my first online game, my first PC game too. i played a ton of it with my friends and family. it was such a novel thing to have a game where we could all play and run around and talk with each other. i don't really play it anymore but i love watching youtube stuff about it still. it was definitely a huge part of my formative childhood years.

myst is an even odder choice that i put here not because i particularly like the game, or have even played that much of it, but because i watched my dad play it a lot as a kid on our old as fuck macintosh. it was actually the catalyst that inspired me to make my own games. i would draw out adventures on paper that had things you could "click" on that would lead to other papers, like an adventure book. those were my own little myst copies. and then of course when our family got a computer with internet i would immediately start looking up how to make video games and stumbled on rpg maker. so yeah, i'd say myst was pretty fuckin impactful.