I was looking at steaks at Costco one day, and some fellow comes up to me and says, "Want to buy a great steak at a great price? Not many people know about this." He showed me the Flap Steak. I was actually surprised at how well marbled it was. Pretty inexpensive compared to other cuts and compared to what you get. Kinda like a well marbled flank steak. It's also tenderized by the butcher and takes on a marinade very well.