We recommend Amazon.com for everything. Prices can be cheaper, etc.
For instance: "The Lord Of The Rings - The Motion Picture Trilogy (Widescreen Edition)" - That's all three movies (though the theatrical versions, not the extended versions) is $58.49 with free shipping at Amazon and $71.98 at Barnes and Nobel. Even if you are a Barnes and Nobel Member and therefore get an extra discount (in exchange for paying a membership fee each year) the price is $64.78. You do get free shipping at Barnes and Nobel as well.
And then there is Barnes and Noble. Prices on DVDs often the same but no shipping on two or more items (if you have everything sent at the same time to the same address via standard ground shipping). On Books, there is often less of a discount, however.
For all other items