Best Online Music Retailers

OK, I did a quick search and could not find a thread on Agon dedicated to this topic, so apologies if this is a rehash. What are your favorite online music retailers and why? Best for physical media - records, CD's, XR and Gold CD's, SACD's and music videos? Best for Downloads? Very curious where others get their music online. Not interested in hearing about garage sales and brick and morter stores here - that is for another thread.