I have heard lots of great things about Amazon and lots of people swear by them but I have had nothing but bad experiences and I'm done with them. Ebay has been great and let me share some of my thoughts.
First of all, Amazon's website is an eyesore, and it hurts to even scroll around there. The pictures on ebay are more abundant, I:E they post more than one picture of the product, and generally at higher resolutions.
My last 3 transactions with Amazon have all gone sideways, either a product not advertised correctly or not showing up at all. Sure I have had maybe 2 or 3 small mishaps on Ebay but in the last 55 transactions not 3. They have been good with refunding my money but once and awhile I actually want the product I order.
Ebay is the place you can find cool finds, not just mainstream stuff. Amazon is the Walmart of online. With ebay you can find collectables and antiques and cool stuff, not just the latest blue-ray or sports watch ( although you can find that on ebay too. )