From a Western European perspective, Bernie Sanders seems like by far the best candidate. I know his views seem a bit extreme for American standards, but pretty much every other developed country has a major party with a platform like his, and most of them are doing pretty well.
Hillary seems like an okay candidate; I don't know much about her, but I've heard both heavy praise and criticism.
Just please, please, America, do not elect a Republican president. The GOP's position on climate politics is the single biggest threat to the human race in this world. Not to mention their endless warmongering and incredibly outdated positions on pretty much every social issue there is. Especially thinking about gun laws and abortion rights right now. They say banning guns wouldn't be of use because people will still find ways to get them, but at the same time are trying to make abortions as hard to get legally as possible. If anyone understands the logic behind that, please explain to me.