Go IndiGo
My partner and I recently spent two weeks in India, taking 5 internal flights whilst there (Jaipur-Kolkata, Kolkata-Shillong, Shillong-Hyderabad, and Hyderabad-Mumbai). Every single member of IndiGo staff with whom we came into contact was professional and helpful. The aircraft were comfortable and the journeys went without a hitch. I was most impressed with the level of customer service when I stupidly left my Kindle on the plane to Shillong. I contacted IndiGo and, when I returned to Shillong airport, the Kindle was brought to me at the gate. They had not only found it, but had cross-referenced my flight bookings to find out when I would be back at the airport and, once I had checked in, they then brought it to me. To say I was impressed was an understatement. If I were to return to India, I would definitely recommend flying IndiGo - the flights are good value, well-staffed, and professionally run.