C-Span offers a yearly updated '"Best President In US History" list.
Overall Ranking:

1 Abraham Lincoln                  
2 George Washington                  
3 Franklin D. Roosevelt                  
4 Theodore Roosevelt                  
5 Harry S. Truman                  
6 John F. Kennedy                  
7 Thomas Jefferson                 
8 Dwight D. Eisenhower             
9 Woodrow Wilson                       
10 Ronald Reagan                           
11 Lyndon B. Johnson      
12 James K. Polk                   
13 Andrew Jackson                   
14 James Monroe      
15 Bill Clinton
16 William McKinley      
17 John Adams      
18 George H. W. Bush      
19 John Quincy Adams      
20 James Madison      
21 Grover Cleveland      
22 Gerald R. Ford      
23 Ulysses S. Grant
24 William Howard Taft      
25 Jimmy Carter      
26 Calvin Coolidge      
27 Richard M. Nixon      
28 James A. Garfield      
29 Zachary Taylor      
30 Benjamin Harrison      
31 Martin Van Buren      
32 Chester A. Arthur      
33 Rutherford B. Hayes      
34 Herbert Hoover      
35 John Tyler
36 George W. Bush      
37 Millard Fillmore
38 Warren G. Harding      
39 William Henry Harrison      
40 Franklin D. Pierce      
41 Andrew Johnson      
42 James Buchanan

C-Span
http://www.c-span.org/PresidentialSurvey/Overall-Ranking.aspx     

Truman and Eisenhower are too high. Truman benefited from what FDR left him and the huge surge in Economic activity after WW2 (albeit a dip in the first few years due to loss of the war economy), and IKE put the Country on  autopilot...which I guess is not a bad thing, but a trained monkey could do the same if no crisis came up.

Kennedy at number 6? We naturally want to canonize our fallen leaders, but I don't know. He didn't serve long enough..what good he did do with space program and the Cuban missile crisis were kind of offset by not having his hand on the stop button for the bay of pigs and Vietnam.

I think James A. Garfield is underrated --- he was a progressive thinker for his time.