I have always liked this jousting diorama, The Bretonnian Joust, by Dave Andrews which won the Open Competition in the 1996 Golden Demon awards. The level of detail is outstanding. There are hoof marks in the ground, created using clay. The manuscript on the back is handwritten.
Across the diorama are lots of figures adding to the story. The pavilion is made from foil, but is painted to look like cloth.
Some more photographs and details about the model can be found here.