The best of the classic roller coaster / park mgmt sims, entirely written by Chris Sawyer – in assembly! OpenRCT2 offers enhancements such as playing all RCT1 levels in it, and even co-op multiplayer.

BG3 easily is the best role playing game of the decade, if not the most ambitious CRPG of all time. Making different choices in each playthrough gives it hundreds of hours of replay value.

The most polished 2D stealth game out there. Great progression mechanics, and the game can be finished non-lethally for an extra challenge. Klei seemingly can do no wrong in terms of game quality.

Perhaps the most complex popular videogame out there, with enough emergent gameplay to satisfyingly fill all of your free time, despite delivering only the most rudimentary of graphics. A masterpiece.

You were expecting Age of Empires II instead, but RoN blows it out of the water with better game design and stands the test of time real well too.

Q3A is simply the pinnacle of arena FPS. Quake Live tried to monetise the genre, Quake Champions attempted combining Quake with "modern" P2W game mechanics — neither will be remembered in ten years.

The best automation money can buy, glorious fun for hundreds of hours alone and with friends, and certainly worth full price – not that there was an alternative with the devs' strict no-sales policy.

MW is the best-designed TES game. Nowadays there is a multiplayer mod (OpenMW)! Its sequel Oblivion pioneered ill-conceived level scaling and pathetic nickel and dime DLCs with the famous horse armor.

As far as 'hard survival' management games go, you cannot find better than Rimworld, and the plentiful available mods lift it on yet another level. Prison Architect has nothing on this.