A cast-iron skillet. No doubt. The sturdy metal not only retains heat well, but it also heats evenly. That results in the beautiful golden brown sear that we so covet on our scallops, pan-seared chicken, pork chops, steaks, and more. You'll often see recipes call for nonstick skillets to sear food to avoid sticking. But they're made of flimsier metals, which means they conduct heat less efficiently, ergo a less lovely sear.