Came across three websites of interest Friday.
Blue Feed, Red Feed shows liberal Facebook and conservative Facebook posts, side by side.
All Sides shows news and issues from multiple perspectives along a blue to red spectrum.
Media Bias Fact Check identifies the political and philosophical bias of various news websites.
I will continue to populate this list as I come across similar sites.
DMOZ is the largest, most comprehensive human-edited directory of the Web.
Yale University Library LibGuide – Ethics & Watchdog Groups Research strategies and resources on media, popular culture, journalism, copyright, digital society, and related topics.