C-Span ranks the former Presidents: Honest Abe gets top billing, follwed by Washington, FDR, Teddy Roosevelt and Truman. How did the George Bushes, Bill Clinton, and Ronald Reagan do? Click the link to find out.
Timed for Presidents Day 2009, C-SPAN today releases the results of its second Historians Survey of Presidential Leadership, in which a cross-section of 65 presidential historians ranked the 42 former occupants of the White House on ten attributes of leadership.
Wikipedia also has a compiled average ranking, which is equally interesting.
Sources
C-SPAN Survey of Presidential Leadership – C-SPAN
Historical rankings of United States Presidents – Wikipedia