I would definitely vote for FlipKart. It has the best site and best devliery model you can imagine. It’s a no hassle shopping where you get what you ordered, if not, you get a replacement at your doorstep. The deals are not great and the prices are a little higher compared to other sites, but it’s worth the peace of mind you get. I am a regular user of FlipKart and it’s my first(and usually the only) choice when it comes to online shopping.
Sites like Snapdeal, EBay etc allows small traders who ship items that are not precisly the same that was shown to you when you ordered, I had this experience with Snapdeal more than once so I stopped using it except to read the reviews. Sometimes Snapdeal even sends used/unoriginal products. The deals may be good, but there is no guarantee that you’ll get what you paid for.