The hands-down best pan for pan-frying steaks is a cast iron skillet. The primary reason is that the heft and make-up of these pans allow them to store up significantly more thermal energy than other pans. These pans hold their heat very well and, thus, are able to deliver more thermal energy to a sear. Another benefit of these pans is that, unlike other pans, they can be pre-heated empty and dry to very high temperatures without warping, allowing you to start cooking with an extremely hot pan.

If you do not have a cast iron pan, the next best alternative is a stainless steel pan with a heavy bottom and a copper or aluminum core. The cores of these pans help evenly distribute heat, and the heavier weight helps with heat retention. What you particularly want to avoid are nonstick pans coated with materials like Teflon. When pre-heated to a proper temperature to pan-sear a steak, the nonstick coating on these pans can break down and release toxic fumes into your kitchen.