This is a great subscription box review site that I actually used for research before ever starting my box. She has TONS of great box reviews as well as a database of all the subscription boxes out there...and if she is missing one, just ask to be added!  Lots of great info on this page and my new favorite is, of course, her wonderful review of Rag Tag Box! Check out the review here:

hellosubscription.com

And be sure to check in to this site from time to time for more great reviews of monthly subscription boxes!