Oh shit no. Washington, Jefferson, Lincoln are the top 3 and would be tough to beat. The greatest of them may be Lincoln. Simply because he saved the Republic so much so, that a Democratic Republic has become the default view of good governance, where that was not true before or during his presidency. Therefore, I vote Lincoln as the absolute best. He made the hardest decisions, the right decisions, against all odds and against even his closest aides and the populace itself.
The north wasn't a fan of the war and most didn't care about abolition and further, at the time, abolition was unconstitutional. He won against all odds.
I think he's the hands down winner of greatest president ever. Could be up for greatest leader ever.
Aside from Trump's demeanor, he can be a good president. Greatest would be he stood down a challenge greater than the Civil War itself and we may be a divided nation to a degree I don't see him having to deal with a crisis of that magnitude. For him to even be great, takes a national or international seismic event that requires leaders to define themselves in the critical moments.
All we are dealing with right now are pithy partisanship and grandstanding in Washington and that's actually good news. Because it means nothing major, requiring us to check our perspectives has happened....yet. Let's have this talk 4 - 8 years from now.