I'm relatively young and new to politics, so my answer isn't a definitive one or anything but I've taken interest in Bill Clinton as of late. I have heard of some of the horror stories coming from people that have worked in his administration which is a shame if they have validity but I really like watching him in interviews. I saw a video where he was being interviewed by Bill O'Reilly and you can tell he is really patient and diplomatic. Even when O'Reilly is being rude or being pushy, Bill Clinton is really good at dealing with it and pointing out the things he disagrees with Republicans on and agrees with Republicans on and he does it in a really smooth and calm way. It's been pointed out many times before by other people that have done much more research than me and are much older and wiser how talented of a politician Bill Clinton is. Jokes aside, he seems very manipulative and that's probably a "good" quality to have in a politician for lack of a better word. Hillary on the other hand is the exact opposite of him, maybe on policy they're similar but she doesn't have an ounce of the charisma he has.
As it was pointed out in another post, Ron Paul is really good, I like him a lot. I loved how he really threw a lot of people off in the 2012 GOP primary. Everyone was so in favor of war in (I don't even remember where) and Ron Paul just pointed out the flaws in all of their plans and how they're manipulating people. He'd then go on to push his non-interventionist stance which I think threw off the establishment guys. I still subscribe to Ron Paul's channel and watch his news updates that he releases every few days throughout the week, though I don't agree with him completely. I have my Libertarian leanings on subjects like education and various other things but I'm not as much of a Libertarian as he is.
The OP also mentioned Mitt Romney and yeah, I think his story is very interesting, he certainly had a lot stacked against him. If you like Romney, I recommend watching the Documentary Mitt sometime on Netflix, it's pretty good.