Marathon Infinity - The whole Marathon trilogy did a lot for defining the story-driven FPS (as did System Shock), but since the first and last title were Mac only for years, they didn’t get the credit they deserved among the pantheon of FPS greats.

Superbrothers: Sword & Sworcery EP - For years, whenever someone asked me what the must-have game was for iOS, this was always my answer. It shows up on a fair number of iOS lists, but doesn’t get the same level of recognition on PC. One of the most well-crafted experiences ever.

Clash at Demonhead - Despite having an Easter egg in Scott Pilgrim, this NES game is largely forgotten. It was one of my favorites in my youth and I am always surprised by how few people have played it, let alone finished it.

Plants vs Zombies on PC.

Great, unique, iconic, still fun to play. Its biggest achievement: I have brought a lot of people into the hobby by making them play this as their first video game and there wasn't a single one not having fun. Tower defense is as a whole an underrated genre if we talk about the best games of all time. It also is a game that offers achievements that add a lot to the gameplay by challenging you to change your tactics.

They of course had to make the second one mobile only and on top ruin it with microtransactions. :( Greed is why we can't have nice things.

Pirate Trainer & Uru: Ages Beyond Myst

I remember trying Pirate Trainer in a Nvidia game booth when VR was new. It was incredible, years later I get a VR headset and its the free game. I don't understand how no one has improved upon it.

Uru was the first puzzle game I thought struck a good balance between physical and mental puzzles. They were set at a level that felt challenging but not impossible and laid out so you alternated really nicely. Myst Online actually went backwards in this

Trog.. I played that game for days

It just occurred to me that Death Really (1995) would deserve to be talked about as well, it's just an incredible little game.

Freespace 1 & 2 deserve a mention here. Old games, so smaller in scope than modern games. But I feel they can compete still.