It may have happened in 2009, but the huge amount of entries and careful judging have pushed back the results of the last Unearthly Challenge. The seven 3D finalists are yet to be announced, but until then you can see the top 15 3D entries over at the Unearthly website!
They also showcase the top twenty 2D entries, and there is some fantastic inspiration there. There are too many amazing images to post here, so here are some choice picks from the bunch.
If you look carefully, you'll notice that a full seven of the fifteen top choices were produced by Polycount members, fighting for the black 'n' green!
That means we could be looking at a clean sweep, if the judges know what's good for 'em...
Another nice thing about this challenge is that it encouraged the participants to post their work-in-progress images and thoughts as they were creating the environments.
Since all the links from the Unearthly site take you to the entrants' respective forum threads, you can take a look at their processes and techniques as they crafted their work. You might pick up a trick or two!