"Burn After Reading" was tops, according to Media By Numbers, with "The Family That Preys" second. But "Family" had a better per-theater average and Nikki Finke argues that the competition between the two films was pretty even.
I haven't seen "Burn," although I want to. I did see "Family" and did not care for it. While it had good things, including great scenes between Kathy Bates and Alfre Woodard, and I admire Tyler Perry's tenacity and his business success, overall it disappointed me.