Even as a non-American, I'm a fan of the many of Madison's (and Hamilton's) writings in The Federalist Papers. For their presidencies themselves, Madison was the president during one of the USA's most important war victories. Washington and Jefferson both were great too. I'm not much of a fan of FDR. In my opinion, he was the closest president to being a large-government dictator who thought he was better than Washington, enlarged the power of the president, blasted the press probably as much as Trump does now, covered up genocides done by Nazi Germany/USSR, detained Japanese-American people simply for being Japanese, etc etc. But Americans elected him 4 times, so they found something likable in him...
I think Teddy transitioned USA from just a country of colonies into a world super power in his term. I'm fond Eisenhower as well, and I often ask how would presidents like them handle today's events. Most of today's events would probably be over their heads though.
I'd say Lincoln is the best. He kept the union together when the south wanted to secede. In the process he also managed to end slavery.
Truman. I will die on this hill. You got a problem with Truman, you got a problem with me. As a local politician in Missouri he once stood up in a room full of hooded Ku Klux Klansmen and called them a bunch of goddamn cowards. He issued the executive order that de-segregated the US military. He relieved of command in the Korean War the universally beloved American hero Douglas MacAurthur when Big Mac got out of control. Time and again he did the right thing when it was far from the politically expedient/popular thing. He probably had the smallest ego of anyone who ever held the office. But best of all, he used to say that if he hadn't been president he would have liked to have been a piano player in a whorehouse. I'm no fan of FDR either but you can't hang that all on him. It was completely unjustified paranoia, but that policy had widespread public support. Badass indeed! But this would be a controversial one. The whole Indian Removal/Trail of Tears thing. Again, maybe 90% of Americans at that time supported Indian Removal. But Jackson defied a Supreme Court ruling in doing it. That takes him down a notch with me. Can't make an argument against Lincoln. He was clearly up to the immense challenges of his time. I could say he did a shitty job of picking generals to command the Army of the Potomac. Except that his first choice was Robert E. Lee.