Though I won't mention all of them, I urge you to check all the links.
Here it goes:
Bill's Prog Blog is, as the name suggests, Bill's blog about all kinds of progressive rock music. He's a very good reviewer and has good links with the community. He posts interviews as well and also has a regular column about Magma. In the last months he hasn't been as active as before, but I hope he resumes his usual pace.
Fire of Unknown Origin is my friend Raffaella's blog. Her reviews make me go pale in shame. She is Italian, though she has moved to the USA a few years ago after meeting her soul-mate on Prog Archives. Her English is better than many native speakers and her reviews reflect that. She has been an Admin and reviewer on Prog Archives and Progressive Ears, a reviewer on Progressor and now a reviewer for Prog Sphere. In her blog she posts reviews of current and past progressive and related albums.
All Media Reviews is maintained by Kyle who writes about all kinds of music as well as other types of media. He's always ahead of the curve with forthcoming albums.
Hemulism is my friend's David blog about all things Avant-Garde in music.
CD Reissue Wish List is the brainchild of Tom, who is a walking encyclopedia about all bands and albums obscure and out-of-print. In this blog he lists out-of-print albums, reviewing them and mentioning the priority of a needed re-issue. He also updates whenever one such album comes back in print.
Angry Metal Guy is a metal-dedicated reviewing website with various reviewers with particular musical taste in metal. They have good reviews and are not shy to tell you their opinions straight up.
Heavy Blog is Heavy is a metal dedicated blog with several writers and reviewers and various types of features. The Number of the Blog, Metal Sucks, Metal Insider and Metal Callout are similar such blogs, good to get updates on the current things in metal as well as some interesting features.
Deaf Sparrow is a very well done website focusing on metal (and related), doing reviews, interviews and special features.
Doomantia is a blog reviewing bands and albums of the Doom spectrum and has recently opened its webshop to sell such albums.
Heavy Planet is connected with The Ripple Effect and The Soda Shop, as well as The Klepto. This fine blog focuses on heavy psych/doom/stoner metal/rock bands with great features such as New Band To Burn One To. One of my favourite blogs.
Invisible Oranges is Cosmo Lee's website/blog with other writers as well, posting features about various topics in the metal world (and beyond). Another favourite of mine which I check daily.
Free Jazz is an excellent blog about all things jazz with reviews and features about musicians.
The Inarguable is one of my favourite blogs, featuring various types of metal and rock. It is well-written and often updated and has interesting reviews, interviews and other features.