Redbus.in is one of my fav site for travel in bus. I chose this site by seeing this ad in the tv. I am using this site from long back from one year. I saved lot of money for rach and every time I traveled.
Every time they used to give coupon for instant discount and I use ro pay through payumoney gateway and saved 20% extra and that is how I got good saving every time I traveled. moreover I am happy with the journey till now and I used to book the buses using the rating given by the passengers already traveled. I can recommend this site for every one who would like to travel in bus.