When it comes to graphics eye candy, we have a heckuva sweet tooth here at TR. One of our long-standing favorites is the demo from Japan simply known as "rthdribl," for "real-time high-dynamic-range image-based lighting." This demo uses DirectX 9 to implement in real time the lighting techniques pioneered by Paul Debevec for offline rendering. Although the demo is many years old, it still is one of the most photorealistic real-time graphics demos anywhere, in my view.
Happily, today, we have a new contender in the same vein, also from Japan: a demo known as "Rigid Gems" that claims to use "hybrid raytracing" and DirectX 11 to produce some stunning visuals.
As usual, YouTube's compression saps much of the detail from the video, so you're not quite getting the whole story visually. You can download "Rigid Gems" from its website and run it for yourself. It runs fluidly for me on a GeForce GTX 680 at 2560x1440. I suspect we may have a new favorite load-testing app for graphics.
Be aware, though, that I have no idea whether this executable is embedded with hideous malware or the like. I just click, look at the pretty pictures, and hope for the best.