I don't particularly want to meet any of them. But if it was very convenient, I'd probably go for the present one, Barack Obama. I think Obama - not now, of course, nobody really appreciates a US President when he's in power - will go down in history a few decades from now as one of your very best.
I don't know a much about any of America's Presidents, though I'm generally aware of those who have lived - and are still living - in my life time F.D Rooseveldt, Eisenhower, Kennedy, Johnson, Nixon et cetera. It took Jimmy Carter to get America out of Vietnam. I see him as a very good man.
Bill Clinton? How can you not like the guy? As Alecia Murphy says, he has "charm."
As for the two Presidents - father and son - who both ordered an invasion of Iraq...well, I'm not very impressed with either of them.
Still, this is just an 'outsider's' opinion.