The only ones worth considering (IMO) are Kennedy, Reagan and Clinton. As for being ballsy, I'd say Kennedy and Reagan are the standouts there. Too bad Kennedy didn't live to take another term. I think this nation would be a different (better) place today if he had. But of those three, each had his strong points, as well as weaknesses. But to me, it comes down to Kennedy vs. Reagan... IMO, flip a coin and choose depending on how you feel about this issue or that issue. I was pretty anti Clinton when he was in office. But in retrospect, I have to admit that he did a good job overall.
As for truly bad Presidents, I'd have to say Nixon has that prize wrapped up hands down. W. Bush was (obviously) a bad President, but also very much like Warren G. Harding: a President who wasn't really President... just a puppet for special interests. Also interesting that W. Bush is often compared to another (bad) President from the 1920's: Herbert Hoover. I'd put Ford, Carter, H.W. Bush and Obama (so far) in the "ineffective" category. Johnson was certainly effective, but he will always have Vietnam hanging over his head.
