Certainly not Theodore Roosevelt.
I like this answer.
He kicked your ass and ended your empire with sheer manliness. Get over it.
To order them (including Bush and Obama so far):
Great:
1. FDR (Yup)
2. Truman (Finished what FDR started, only with a better Cold War policy)
3. TR (Not quite fair, since he happened to get a smooth decade, but I like his trust-busting)
4. LBJ (Failed in Vietnam, succeeded in everything else)
Good/Decent:
5. Ike (Not too much to say, but yeah)
6. Clinton (Pragmatic and intelligent enough to get the job done, and don't care about Monica)
7. JFK (Got the Great Society and CRA rolling, but LBJ gets the credit for doing it)
8. Nixon (See Clinton, only corrupt)
9. Obama (He's gotten a lot done, but he's too much of a pussy about it)
Average:
10. Bush Sr. (Eh)
11. Ford (Meh)
12. Taft (Shmeh)
13. Wilson (Did a ton of good and a ton of bad. However, screwing up Europe tilts it a bit towards the negative)
14. Carter (Too much of a softie, and overall did little. Would have been a better VP)
sh**t:
15. Reagan (Set up the current economic crisis, failed to act on AIDS, and supported Saddam and apartheid)
16. Hoover (Fiddled as Rome burned)
17. Coolidge (Terrible policies that helped start the Great Depression)
18. Bush Jr. (Reverse Midas Touch?)
19. Harding (Blatant corruption, helped set the stage for the Depression)