This question is for Indian cell users. Please tell me who is the best cell service provider in India?

I am utterly confused after researching the offers and tariff plans of various cell service providers of India. I have been using Tata indicom pre paid service (CDMA) for the past 4 years. Now I want to change my service provider because I am not even able to contact my husband at his office just 2 kilometers away (My husband also is a Tata indicom subscriber). I am fed up with the message I often get when I call him - "the person you are calling is not reachable" or "the number you are calling is out of coverage area". So, please guide me which mobile service is better when it comes to connectivity as well as budget - Airtel, Tata, Vodafone, Idea, Reliance, BSNL or any other?