Who are your favourite rationalist bloggers?

I want to check out more ra­tio­nal­ist blog­gers.

Please list no more than one per an­swer. That way I can see from the up­votes/​down­votes which ones are the most pop­u­lar (and hope­fully which ones are most worth check­ing out).

I know that pop­u­lar­ity isn’t a perfect sig­nal, but hope­fully it is a bet­ter sig­nal here than on the rest of the In­ter­net.