The obvious answers are the games we endlessly replayed historically: Mario Kart, Goldeneye (VS mode), Halo (VS), Smash Bros.

If you specifically want ones on PC, I'd suggest Starcraft, Age of Empires, and probably Counter Strike (I wasn't into that one, but it had a huge following).

Many board games fit the bill as well. Codenames (physical or online at horsepaste.com) comes to mind, and another commenter also mentioned chess.

Basically any games that were made before endlessly grinding became a thing (yep, that's only been a thing for a decade or two).