Rayman Pirate-Community

The original Dark Souls, Legend of Grimrock series, Civilization series.
And World of Warcraft.

Rayman 2: The Great Escape.

If I had to pick one, it'd probably be the original Crysis. I've never experienced a game so incredibly fun and, for me personally, sporting so much replay value I still come back to it regularly ten years later, and not just to speedrun, but just to have a good time. The physics, the level design, the interactivity - I can't get enough of all of it. I find that the graphics still hold up and look pretty astonishing to this day.