The Witcher 3: Wild Hunt: This open-world RPG is known for its deep storytelling, immersive world, and complex characters. It's often praised for its mature themes and morally challenging choices.
Elder Scrolls V: Skyrim: A classic open-world RPG that offers a vast, immersive fantasy world to explore, with a rich lore and a high degree of player freedom.
Dark Souls series: These challenging action RPGs are celebrated for their intricate level design, deep lore, and tough but rewarding gameplay.
Divinity: Original Sin 2: A top-down, party-based RPG with turn-based combat and a strong emphasis on player choice and interaction. It's known for its complex narrative and deep character customization.
Strategy Games:
Sid Meier's Civilization VI: This is a turn-based strategy game where you build and manage your civilization throughout history. It's highly addictive and offers a deep strategy experience.
Total War: Three Kingdoms: A real-time strategy game with a focus on historical battles and diplomacy. It combines turn-based empire management with large-scale real-time battles.
Stellaris: A grand strategy game set in space, Stellaris allows you to create and manage your own interstellar empire, engage in diplomacy, and explore a vast galaxy.
XCOM 2: A turn-based tactics game where you lead a team of soldiers against an alien invasion. It's known for its challenging gameplay and tactical depth.
Crusader Kings III: A grand strategy game set in the medieval world where you manage a dynasty, make alliances, and navigate complex feudal politics.
I recommend Hearts of Iron 4 as it requires doing multiple tasks at once such as micro-managing your divisions. It's a pretty fun game at the same time where you might play the WW2 in alternative history.