A site like Snopes with its pretend factfinding, in other words, heavily left-liberal and far-left of late, is in a way today honestly dishonest, in that its dishonesty in pretending to be unbiased is a known-known.
Rational Wiki is not so easy to categorise but I note some recurring comments in my travels:
# RationalWiki is a pollitically and ideologically geared webpage that produces propaganda for the USA left wing pollitical spectrum.
# When it comes to social and political issues, RationalWiki is really a mixed bag. Their articles are, of course, as they are everywhere else, overwhelmingly partisan, but, if you happen to agree with their liberal perspectives, then you will probably find them both entertaining and informative. If you do not agree with their liberal perspectives, well, they probably will not have much to offer you then.
# In the area of religion, RationalWiki editors often misunderstand, misinterpret, or oversimplify the religious teachings and arguments that they are debunking.
# When it comes to the subject of science, they’re almost always accurate. When it comes to politics, however, things get complicated.
# It does have a liberal bias, but they have talk pages for every article, where you can raise your concerns, and correct any blatant misinformation.
All those are opinions I saw in passing, this one perhaps nails it better:
The url looks promising until you get into what the author is saying and then it comes out as ‘anti-denialist’, i.e. they would see Anthony Watt as a bete noire, most people commenting at N.O. as rightwing denialists.
However, they sometimes do make good observations in less politicised spheres, so I’d say approach with caution.