Aside from Heroes 3, I haven't played anything else for many years now. Other games get tiring over time. But for example, I consider the old games to be the best! For instance, Quake 1, Doom 1, Hexen, Age of Empires 1, Majesty, Diablo 1. Maybe the graphics are blocky, but what spirit, what interest—you can feel that the developers put soul and meaning into the games. Medal of Honor and Disciples are also pretty good.
Age of Empires 1-3
Majesty (+ addon)
Disciples 2 (+ addons)
Cossacks (various).
But for me, CHESS and HEROES 3.2 Complite will remain eternal games (the ones that never get tiring).
And BILLIARDS (if in real life).
