This is more the kind of site I expected Corr to have nominated, but since she hasn't - here. TCOP is a blog run by artist and critic Sharon Butler, based somewhere around New York. I think she's started doing videos as well, a la James Kalm. She also writes for the Brooklyn Rail.
Shazz is a tireless blogger, there are always reviews lifted from all over the US and occasionally abroad. She specialises in painting, in particular abstraction. But she is a great barometer for all sorts of NYC art scene issues. A bit like Edward_Winkleman, but without the sales pitch. Worth going to for echoes, second opinions and stuff. Shazz is also heavily into the networking thing so you can follow her on Twitter, Tumblr, FB, etc. She is a nice lady.