PC games I liked very much during my life are these, and probably there would be more of them.
GTA San Andreas, LCS, VCS, Vice city, IV
Witcher I
Pokémon Gold, Red, Sapphire
Settlers 5: Heritage of kings
Age of Empires III.
Europa Universalis III, IV
Gothic III
I played recently a lot of Europa Universalis IV, but it takes a lot of time. It is great fun, because I have to calculate a lot of things carefully, and one bad war can render me doomed in the long run.
And I played GTA Vice City a lot this year, I played this formerly now and then, I did finish the storyline once, but I used cheats in that walkthrough, maybe I will pull it off now even without them.