(GeoComp2 posts feature Quake 3 levels with outstanding geometry inspired by modern architecture practices; unfortunately GameSpy deleted the original GeoComp2 pages, so these blog posts are an attempt at creating a historical record.)
Neorganic Epiphany, by Dubbilan, is blobitecture / "parametricism" with a "Miami Vice" sensibility. The floorplan isn't what makes this level special -- it's a decent central arena plan with a handful of small side atria that feed back into the middle. But the style does make one rather important difference in gameplay...
See, most arcade DM maps -- especially those in the BSP era -- are rather blocky, due to the nature of BSP construction. It's easier to manipulate rectangular shapes than curved, slanted shapes. This is mirrored in real-life construction practice with four-cornered rooms and long, straight planes for walls that meet other walls at 90 degree corners...

Line of sight is essentially important in high-octane arcade contexts, like Quake 3, because your opponent likely has her railgun aimed at head-height as they slice the pie.
On Neorganic Epiphany (and, to a lesser extent, some of the curvier Covenant-themed levels in Halo multiplayer too) this technique is much more difficult to use because there's no "corner" to pivot on. Perhaps this explains why a lot of players liked this map for rail-only servers -- longer sight-lines, more danger, a sort of balance between a corridor-crawl and a space floater.
And again, in an age of desaturated brown FPS's, here's one that utterly thrives on the use of color. Seriously -- magenta! When was the last time you saw magenta in a big budget commercial FPS that wasn't Halo?