GPU-rendered Cornell Box
This is the product of an attempt at using OpenCL for path tracing. It is extremely high quality, and is in standard, non gamma-corrected form (so you might want to adjust the gamma of the render to make it look more realistic).
In case it isn't immediately obvious, this is a box containing two reflective spheres (left and right) and a glass sphere (middle). The front and top faces of the box are checkered. The little spots of light on the green and blue sides are the result of the light being reflected off each reflective sphere and then concentrated through the glass sphere.