1. Barack Obama. He is a very nice man with integrity. A good character, no matter what you think of him politically.
2. George W. Bush. His policies and decisions were horrible, but the dude himself was pretty funny and not personally offensive.
3. George Bush Sen. Nice man in general. Some shortcomings already pointed out, but overall not a bad guy.
4. Bill Clinton. Well, mostly polite but inacceptable behavior to some women.
5. Ronald Reagan. In public he was mostly like a “nice grandpa”, but a very distanced man.
6. Donald Trump. No words. Spreads bigotry, insults, offends and assaults women, mocks reporters, insults political rivals, attacks other people (actors, union leaders, etc.). The Trumpster is a bully. Through and through.