Hmmm...
Other than girders, springers and leaf, (are you thinking Indian's leading link?) you've got the basic telescopic fork we are all familiar with, BMW's telalever & duolever, center-hub steering, and some more. Seems to me they can all be built stout if weight and size isn't a consideration, but I think one of the most robust would be a Earles fork that BMW used until the late 60's.
Found an article on suspensions in Wikipedia:http://en.wikipedia.org/wiki/Motorcycle_fork