DTH (Direct to Home) satellite television service provider has revolutionized the way of watching television in high definition picture, video quality and Dolby digital sound surround quality.
Check this thread: Discussion - Digital Cable TV Vs DTH
Picture quality is better in DTHs than cable.
In DTHs, TS is having good SD PQ & in HD both airtel & TS are good but airtel's PQ on regional HD channels is better.
In this new regime, when prices are same across all DTHs I'll suggest you to go for TS as it provides maximum channels & it's service is also good.