I'm going to toss in:

Vote411.org, the site was established and is run by the League of Women Voters, an organization that has worked for over a century in registering voters, providing voter information, and advocating for voting rights. They provide information about the candidates and their stances on different issues. A candidate may choose not the provide answers to their standardized questions, but then I would question what the candidate is trying to hide.

ISideWith: answer a bunch of multiple-choice questions about your values, goals and opinions, and they'll tell you how well each candidate 'matches' your opinions. There are often additional questions if you'd like to refine your stance beyond the original options given.