I think the argument could be made that Hogan's greatest feud was against Heenan and not any one particular wrestler. What one moment or match would you think would be the peak of that feud? Do you think Hogan had a greater opponent in hindsight?
Anyone else humming "Hogan and the Brain, Hogan and the Brain, one is a genius and the other's insane" right now?
Obviously the feud peaked with Andre the Giant at Wrestlemania, which was Bobby putting all his chips on the one number and swinging for the fences or whatever other mixed metaphor you want. And then his best shot lost and that was pretty much it for his serious challenges to Hulkamania.
I still do think that Randy Savage was Hogan's greatest opponent, though, because he actually outsmarted Hogan for a time by becoming his friend and using Hogan like a secret weapon to win the World title before going crazy and losing it back to him again.