In most stadiums, the worst lower level sections are the ones located directly behind the basket. At the AT&T Center, behind the basket seating is about as good as it gets in the NBA. A wide walkway directly behind the basket means that no fans will be directly behind the hoop.
Both sides of the court feature loaded nachos at a concession stand, and you'll find a bar on the 113-115 side. The first row in each section is 6, except Section 113 where the first row is 14.