Permanent Style - I wonder how much of a PR discount he gets, because he must have a few hundred thousand worth of bespokewear if valued at full retail. Those prone to envy may wish to avoid.
Gentleman's Gazette - good for historical details and in-depth discussion of the basics.
Made by Hand - great in-depth tailoring blog with garment tear downs and analysis. Alas, few posts as of late; @jefferyd must be too busy at his day job.