I'm going to go at this from a different direction. The question isn't who deserved to be champion but who should have been champion. From a business standpoint the answer is Rowdy Roddy Piper. There may not have been anyone more hated than Piper was in 1985. It could have drawn huge numbers having Piper win the belt and drop it back to Hogan.
I agree with every person mentioned by others. But of the ones mentioned, Piper would have drawn the most money. I know he wouldn't have had a very long reign. He would have won it just to drop it back to Hogan. But what a good way to get him even more heat at the height of wrestling popularity.
With that said, it would have been interesting. By Wrestlemania 2, Piper was still a top heel in the company, but he was being cheered. Putting the belt on him may have backfired. But if they would have done it soon after Wrestlemania 1, it could have been huge.