This is a decent shot from my procedural planet, Khundali IV.
It has an essentially infinite procedural texture, and the planet
itself is about the size of earth.
Its part of my research engine called Immersion, follow the link to learn more about it and get some more screenshots.
Or just try the demo.
The engine doesn't have any special effects per se. It could really use atmospherics and a star background, but that will have to wait. It still has a little ways to go still before its ready for use in a game (performance optimization, geforce stuff, etc). My approach so far has been to focus on some very specific and important component(in this case its planet sized terrain texturing/modeling), rather than throw in a bunch of mediocre special effects that everyone else has.
For my next project, I am going to start working on a volume renderer to extend the Immersion engine. I think the hardware is about ready for this, and its absolutely necessary for rendering just about everything interesting: forests (millions or billions of realistic trees, not the poor excuses we have in games now), clouds/gases, the rings of saturn, etc.
If any of you coders out there are interested in working on this or other related projects, let me know.