The SU-100 was a Soviet tank destroyer armed with a 100 mm anti-tank gun in a casemate superstructure. This is one on display at the Imperial war museum in Duxford.
The SU-100 was used extensively during the last year of World War II and saw service for many years afterwards with the armies of Soviet allies around the world. It is still in active service today in many countries.
Reading the Hot War books from Harry Turtledove has inspired me to think about gaming some scenarios from the books. British Comets and Centurions versus T34-85 and T54 Soviet tanks, along with tank destroyers such as the Su-100. In the book there are also Sherman tanks manned by (West) German forces.
Battlefront make a very nice plastic 15mm version of the SU-100.