Pretty sure Hilary will seek the nomination for the Dems. I can't imagine who else would try to run against her, but someone should just to preserve the democratic process.
For the Republicans, the names I'm hearing are Jeb Bush, Chris Christie, and Paul Ryan. Ted Cruz is another possibility. I'm not American so I wouldn't vote, nor am I republican, but I would support a Chris Christie bid, though I'd rather see him in Congress. He's shown excellent examples of putting partisanship aside for what's best for the state of New Jersey, and any accusations he has made against the current administration have been more than fair, and certainly in the interests of his constituents. If Congress could behave more like this man, I think we'd see things done, regardless of which party has the White House.