Can't think of many other cars that would have quite the same world wide market appeal.
The tamiya rough rider/sand scorcher were special csrs because they were the first really popular off road cars that were raced in significant numbers - when I started racing that was really all there was so there are plenty of peolpe who raced them back then and wanted a retro one.
The rc10 was a significant advancement in off road cars - it made a lot of the other cars around at the time look like toys. That plus the fact it seemed to be so sucessful over such a long time scale. Oh yeah, it is american so a huge home market.
There have been loads of great schumacher cars but not sure they would have quite the same world wide appeal. Maybe the original CAT but not sure how many peolpe would have the patience to build one
Rob