Even if you don't like your party's nominee. If you don't vote, you forfeit any rights to complain about what the government is doing for the next four years. You got two candidates going for each open office. One of the two has to be better than the other. It is your responsibility as a citizen of a democracy to vote for the better of the two candidates. Can't tell which candidate is better? You haven't done your home work. Go to each candidates website. It's the 21st century, they all got websites now. Read their campaign promises. You gotta like one set of promises better than the other. Google on the candidate's name. See what kinda dirt comes up. See who endorses them. If all fails, flip a coin. But go out and vote. If you don't, the worse guy will win.
If the choice for president comes down to Trump vs Hilliary, neither of which I like much, you gotta make a pick. And vote your pick.