Austin Texas is still one of the biggest Indie Film mecca's in the U.S. as well as New Mexico for all the crew etc. from their tax incentives.
New Orleans and Louisiana's tax breaks have created a nice infrastructure for independent films.
The problem is this amorphous term "indie film", which can mean any where from $300.00 to $13,000,000.00 so we have no idea what we're attempting to describe for you. Most states that have a tax incentive for filmmakers need a budget of $200,000 or more to qualify and each state will vary as to what this is and how much it's for.