Where should I buy my CDs?

Anyone have any insider places to buy CDs online for cheap? I usually use Amazon.com but found under the 'New and Used' link that Newbury Comics has a online site with all of their prices beating Amazon by a few bucks.

I checked InSound.com as well bcause I know they specialize in indie but they were the same price or higher than Amazon.

Any good sites I should know of?