I've got to choose John Sidney McCain.
President John Sidney McCain would have been a conservative, yes, but a conservative who could work with Democrats and liberals for common goals. He would not have polarized the nation between the conservatives and liberals like Clinton, Bush II, or Obama. He as a father figure would have united the nation and helped reach rational compromises between the two extremes on many issues. He would have been more or less like President Barack Obama in ending the recession though the Stimulus Plan would be smaller.