I agree with the rankings. Lincoln was the best IMO. He presided over some of the most difficult events of our country's history.
Truman was very unpopular when he left office but he is now near the top. Carter has fared batter as time went on. Should be interesting to see how W is looked back upon in 20 years.
Not sure why Truman is so highly rated. props for dropping the a-bomb to end WW2, but I don't think he was a good president. completely f'ed up the Korean war.
If Bush JUST had Iraq under his list of screw ups he might get some slack down the road from historians - but the way things are going with this recession, I don't see how he'll be viewed favorably later.