I'm suprised Teddy Roosvelt isn't more popular: the main reason yout have large tracts of wilderness (like Yellowstone) in the States is his influence. Consider also enforcement of trustbusting acts and general commitment to a level playing field in business and the economy.

Some aspects of his foriegn policy don't look so flash, but not in a way that most Americans would find offputting...

James Garfield or William Henry Harrison, can't really decide which.

Boy that's a tough choice. But really, Harrison accomplished so much in his month as President.:D