And just to prove the Quake 4 stuff, these are the first few screenshots chosen at random from google image search.
Notice the rounded wall on the right. It's round so it's automatically more interesting (something Halo 3 doesn't do) and notice all the textures being used just on that one wall. It takes an insane amount of effort to make just that one wall, but it's worth it. Look how nice that wall looks just because of good texture choice.
Notice how these walls are in no way flat. Halo 3 at least angles a lot of their walls in so they aren't completely flat, but they are still just a single plane. Adding those little alcoves makes them so much more interesting.
More good texture choices here. Even the ceiling is nice with just its one texture because it's rounded. The other textures are interesting because they're mixed with other textures and they're just more interesting.
And once again, a mixture of textures and shapes to make a space that feels more real.
I'm not saying Quake 4 is a better game (Quake 4 was actually not that good of a game) but its inside environments were just so much more interesting because you can tell they actually took some time to make those. If Bungie had put the same amount of detail into the inside areas as they did their outside areas, the game would have looked so much better. Instead, we just get boring textures everywhere with boring shapes and minimal prop placement that makes every area look exactly the same and feel unreal.
-edit-
Bah, you'll have to view image to see all the images posted.
