Bush ran against Peace, Prosperity, and sort of ran against Incumbency and won. Trump was lucky to run against an opponent that was almost as hated as he himself was/is, and Hillary was in some respects the Thomas Dewey of our times, in a sense that her campaign took so much for granted. So, that means Bush gets my vote.
This is funny, you have posters constantly saying that it should be taken for granted that Hillary would've lost to a normal republican, and the bulk of the other republicans themselves were also running on that assumption, all they needed to do was engage in some empty flattery and that was enough to win. The only exceptions to this may have been Christie and Cruz who wanted to run more aggressive campaigns against Hillary.
By the way, it should be noted that Hillary changed her entire electoral strategy specifically because of Trump.
https://www.buzzfeednews.com/article/rubycramer/how-a-decision-in-may-changed-the-general-election