I've been using Tata Indicom (VSNL) Broadband service in Bangalore for the past few months. And I'm really happy with it. I have the Explore Plus 1000 plan, where I get 512kbps speed and 1 GB download limit per month. The speed's good (I usually get that much download rate).
The best thing about them is the customer service. Any problem I've had till now, they've followed it up well and rectified the problem within a day in most cases. They also give a call once they've rectified the problem.
The downside: they spray cables all over your locality. The DSL cable that comes to my home jumps over trees and electric poles. One of the poles was removed recently, and the Electricity guys (BESCOM) just clipped the cable. (Needless to say, the Tata guys responded within a very short time to get the thing up). However, this just is not good management of the cables. There also is some 30 feet of cable lying wound up on the terrace (for future expansion?). Ah, just hope they get that bit of detail sorted out..