Hi,
While I have Tata Sky, my cousin has Airtel.
It depends on what your options are weighed against the options/features that are offered.
It was after sales service that I got comfortable with the person thru' whom I booked for Tata Sky, while for my cousin it was the WordSpace Music Channels that got him hooked on to Airtel, because when we compared the price and bundling the price was to close for a similar set of channels, also we did see the picture quality at some of the outlets and there was not too much to distinguish between the two.
So compare all the different inputs like bundling, price, Service, features and then list down your priorities, which will help you to arrrive at a decision else most of the times we end up becoming more confused as we explore more and more options as it was in my case.
Cheers