Top 40 here in their ultimate rank. They have breakdowns such as by RSS subscriptions, unique visitors, and links so if this isn't enough there are plenty more at the site.

Photopreneur is one of my favorite photography blogs. Be sure to read this whole article which includes who or what inspires these inspiring photographers.

Also includes Syl Arena, David Hobby aka the Strobist, and others.

joemcnally.com
mpex.com
strobist.com
pixsylated.com
lumiquest.com
pocketwizard.com
honlphoto.com
flashflavor.com