When it came to 3D advancement and environment stuff, I had to pick the CryEngine to talk about.
http://www.crytek.com/cryengine
This site right here will take you to one of the three CryEngines available to learn about. Right now CryEngine ® 3 is the most advanced engine out of all of them. Being that I have played all of the Crysis games that have came out recently, I have to say that the graphical enchancements and performance improvements are ridiculous. I would write a lot about each of the engines, but just clicking on one of the links on the site pretty much sums it up extremely well.
Here is a video to show how the most recent CryEngine (3) is. Its ludicrous to see how realistic game graphics are becoming. I can only imagine how realistic game graphics are going to be in maybe ten years from now..
And..yep. Here’s a gif. 
