My 4th favorite is Grant. Although his administration had problems, I take presidents' entire lives into account. Grant won the Civil War, and even as President, he defended the civil rights of blacks and Native Americans.
^^^^^
This.
Grant is the most underrated President in history. Here is a man who fought the Ku Klux Klan and was committed to Civil Rights, so much so that he secured (at least Constitutionally) voting rights for non-whites in an era when it was nowhere close to popular.
I think that alone makes up for the corrupt appointees and his bumbling of the 1873 Panic.