Well, there are certainly games with more and better atmosphere, but since we're talking games that don't get enough credit, I'd say these two:
Hunted: The Demon's Forge
The art design combines inspiration from the pre-Columbian architecture of Central and South America with an inky pre-Raphaelite style of coloration and line. It helps make things familiar and alien at the same time. That was also the goal of the narrative and gameplay, but they didn't quite pull things off.
Mirror's Edge
The bright light and clean lines of most of the levels make a brilliant change from the dark, crowded, and oppressive feel of a lot of level design, and it really calls attention to the different kinds of spaces that can be seen as dungeons.
Hunted: The Demon's Forge
The art design combines inspiration from the pre-Columbian architecture of Central and South America with an inky pre-Raphaelite style of coloration and line. It helps make things familiar and alien at the same time. That was also the goal of the narrative and gameplay, but they didn't quite pull things off.
Mirror's Edge
The bright light and clean lines of most of the levels make a brilliant change from the dark, crowded, and oppressive feel of a lot of level design, and it really calls attention to the different kinds of spaces that can be seen as dungeons.