On the other side, could Trump actually get the nomination? I guess that depends on his supporters. His rally's bring in lots of people, but are they there because they believe he should be President, or because he's a celebrity? Are they even going to vote? At least with the other candidates, their supporters are probably planning on voting. I don't believe Trump when he says he won't run as an Independent if he doesn't get the nomination. I don't see him giving up until it's all over.
I think Marco Rubio could win the nomination, but I haven't got a clue which side would actually win the election.
I don't know of anyone that I believe in enough to wish he/she would run for President. Of the people who are in politics today, most have their own agenda. If that agenda happens to coincide with "the good of the country", trust me, it's probably an accident.