I use FLIPKART from last 2 years. It provides genuine products.
And it is very user friendly. This site is Secured for the online buying of product.
The customer care service is also good. and the ordered product is reach at your reference address within the estimated timeline. And the best thing about this is, you can track your order.
Recently I buy one Smartphone from flipkart. it is genuine and delivered before given timeline and it works very well.