St. Everywhere (or, Six Degrees of Tommy Westphall)

It seems that in the last episode of St. Elsewhere, the whole series was revealed to have been a dream in the mind of an autistic child, Tommy Westphall. These people have traced through the intricate web of crossovers and spinoffs and discovered that a huge swath of the television universe, including The Newhart Show, was by implication all part of Tommy Westphall’s dream:

http://home.vicnet.net.au/~kwgow/crossovers.html