I'd rather support a known factor, so I understand what to expect; than a hate-mongering, xenophobic, crypto-fascist (I really hate this term, but unfortunately it's highly appropriate here) who has repeatedly bankrupted his personal business ventures, has never held anything resembling political office, shows nothing even remotely resembling an understanding of either domestic or international politics, and has run one of the most vicious and divisive election campaigns in living memory. The Donald is a hateful bigot who is utterly unsuited to running a neighborhood association, let alone one of the most powerful and influential nations on the planet. Hillary, at least, has some ability to form working coalitions and manage affairs of state in a survivable manner. She won't do much good for the US, but she will not wreak the kind of harm that is inevitable under Trump, unless he has an overwhelming majority of progressives in both houses of Congress to oppose him.
Unfortunately, if it does come down to Trump vs. Clinton, Trump's pseudo-populism is going to be a lot stronger and more effective than her establishment machine politics; and we're more likely to get stuck with Trump.