Guide me to select the Internet service provider.?

I am going to take internet connection to my home. I enquired with Airtel and reliance and tata indicom too. As per my budget reliance data card stands first, second is airtel and 3rd tata indicom. How is this reliance data card ? will it works good ? is 256 kbps speed is good ? wifi connection is good or what ? I like to take BSNL connection but they take min of 1 months and max of 3 months to give the connection. Kindly guide me in this .........! Thanks