I am using airtel broadband from past six months and today I am really satisfied. I am using 256mb unlimited connection which comes with fixed 649 INR as rental, with tax it comes upto 715 INR. With that it gives 100 INR calls free where call charges is Re 1 per call.
For me its a decent plan and unlimited means truely unlimited, there is no upload or download limits and with that free calls, the rate is really competitive.
The most important part with the airtel is "After Sale Service". I am hugely satisfied with the service they are offering. If there is any problem during the office hours with the phone or broadband connection, it will be solve within 2-3 hrs, or else maximum time they require is the next morning, no issue if next day is a holiday.
Again for service related issue, if u call customer care, then its ok, or else if u call any service engineer(if u have the nos, most of the time they give u that at the time they visit ur place) then also ur problem will be solve within the time I mentioned earlier.
Connectivity is superb, but at times it falls. That is the only problem with airtel. Generally I used to get around 0.35 - 0.40 mbps of speed but at times it drops around 0.16 mbps as well. First time they charge only 500 INR for installation, modem and telephone set - I think its a great deal.
Now the rental is reduced and the speed increased. Present rental is Rs 499/ - and the speed is 512 kbps unlimited. Service is still excellent. No doubt, Airtel remain best for me.