I don't find Jim or Robin in the least bit funny, but suspect that I may be in a minority on here.
My views are formed mostly from their chat show appearances. I did like Williams in Dead Poets Society (not comedy) but that's about the top and bottom of it really.
I start to watch their films but invariably give up after about five minutes as I don't get all the adulation heaped upon them.
What are the elements of their comic genius that I'm not getting? Both seem, IMO, to confuse funny with loud faux wackiness and stupid gurning.
The Emperor's new clothes spring to mind here.