I am using Airtel for few years approx five years.I hope Airtel is no 1 mobile operator in India.because the operator is different from other operators.The offer price are low and tower signal is good and customer service behaviour is also good and always get help for them.Airtel comes in first Airtel Open Network and now the operator start free reward tune service.So this operator is top of the other operators like Vodafone, idea, aircel etc.