I have just subscribed for an 8mbps line from Airtel. They are the best service providers I can think of despite there being a plethora of ISP one can choose from(in Bangalore).
The process was simple as this:
I called the Helpline; after about a day someone called me, came over & collected the documents. The next day itself they finished the wiring and I was live the day after.
The story goes on. After a couple of days, my speed dropped to 512kbps. I called Airtel again; within a day someone called me & fixed the problem.
The best part about Airtel is that once you call them, someone keeps track of your problem till it is settled.
I have moved on to Airtel from You Telecom. It was nightmare until I was with You Telecom. I sleep much easy now.
So my advice is to move to Airtel Broadband if they offer it in your area.