This is a followup to @SorosFootSoldier@hexbear.net 's recent thread for completeness' sake.
I'll state an old classic that is seen as a genre defining game because it is: Myst. Yes, it redefined the genre... in ways I fucking hated and that the adventure game genre took decades to fully recover from. It was a pompous mess in its presentation and was the worst kind of "doing action does vague thing or nothing at all, where is your hint book" puzzle gameplay wrapped in graphical hype which ages pretty poorly as far as appeal qualities go.
So many adventure games tried to be Myst afterward that the sheer budgetary costs and redundancy of the also-rans crashed the adventure game genre for years.
What mods are you referring to? I only really played it shortly after release.
I'm mostly referring to master level/randomizer mods. These don't change the game in a major way, so if you don't like the gameplay you probably won't enjoy the mods. Really, all it does is up the difficulty. I love it, but it can be hard.
If you want another try at that almost arcade like, fast FPS gameplay, I'd recommend Turbo Overkill. Indie game, goofy yet fun story.
I was actually thinking about playing that not too long ago. Maybe I'll give it a go
It's very worth playing! One of my favorites of the year for sure.