My vote would be for Reagan...by a whisker...because of:

1. His foreign policy maneuvers.
2. His encouragement of massive fiscal irresponsibility in the 80's.
3. His general mental incompetence.
4. His very nearly getting us into World War III (in my opinion) by pressuring the Russians very hard. We were lucky that Gorbachev was on the other side, and not inclined toward such rash and aggressive an attitude in international give and take.

Was he likable in a number of respects? Yeah, probably.