Myst/Riven
You know, it's such a shame that they had to go 3D and free-view in the Myst series after Riven. I lost interest in the series after that. Riven remains one of my all time favorite games, and I have a feeling I would have enjoyed the games that came after that had they just kept making them in the same style with still-image progression.

Anyway, yeah. Some beautiful stuff to be seen in those worlds. Can't leave them out.