I am using Amazon from last couple of years and I must say they have improved a lot. Their prices are much lower than other sites and they sell original and quality products. One of the main advantage of amazon is their customer service, which I think is the best.
Whenever I had to return something, it was easily done. The only thing they need to work on is delivery time. Sometimes they take really long to deliver products.
Personally I would say if you are shopping online you should give amazon a try.