Obama was the best US president in my lifetime definitely from what i know, considering Clinton, Bush and Trump, but he was still pretty bad but then again, who was good in the last century...
Like Robby said, even FDR has blights on his record, from refusing to propose anti-lynching legislation for political reasons, or Japanese concentration camps for example.
It really depends on from what benchmark you judge them.
From a humanitarian or populist standpoint? They all suck and are bad, by varying degrees. Unfortunately, Trump has shifted the benchmark so far that they look pretty good now...