one sided does not mean unfair. Just because say one candidate is more untruthful than another doesnt mean that the website denoucing those untuths for both candidates is unfair,
best sites for Truthful information is Factcheck.org and Votesmart.org
You should try looking at online encyclopedias and such since they try to give as many facts as possible.
I'd honestly go with Wikipedia because they actually monitor what is written in their articles and give heads ups if the content seems biased or if it doesn't have sources.