If you just wanted blogs (i.e. no twitter+tumblr) the following are blogs I personally like that post frequently in rough order of how useful/insightful I have found them,

• mindingourway.com
• slatestarcodex.com
• srconstantin.wordpress.com
• thingofthings.wordpress.com
• malcolmocean.com
• agentyduck.blogspot.com
• https://blog.jaibot.com/
• lukemuehlhauser.com
• meteuphoric.wordpress.com

There are a few that are very infrequent but very good when they do post,

• relentlessdawn.wordpress.com
• http://www.theunforgivingminute.co/
• https://alexvermeer.com/blog/