For me it’s Diablo II. Granted I’ve played my fair share of D2 since launch, and also recently on a private server with a comrade from hexbear, but I still feel like years later the game didn’t grab me as much as D1 did.
Granted I don’t hate D2, but for a game that I keep coming back to, D1 takes the prize.
I love and truly adore a niche Space RTS game called “Star Ruler” that came out
10-odd14 years ago. With the ‘Galactic Armoury’ mod, it’s so fucking cool. You get to run your empire while designing and build ships of increasing complexity, and eventually insane sizes, custom fleets with a mothership with a repair bay with a big laser (or ten thousand tiny lasers) or you can harvest/blow up a star and eventually you can build giant thrusters on your planets and fly your planets around like they’re spaceships and fill them with rocket silos and shield generators and ugh. The only game I’ve enjoyed to seriously incentivise fundamental tech tree specialisation, too.Star Ruler 2 had none of that, and made me spend most of my time dealing with a frustrating diplomatic cards system, and it had a decent ship builder, but it just wasn’t the same. It’s probably objectively an okay game, but my disappointment was huge, all I wanted was a better engine, sleeker UI, tighter interfaces, nicer graphics, etc. and it was instead basically just a different game.
I still regularly replay SR1, something about it captures an aspect of my imagination nothing else has.