Carbon steel is traditional. It's what I use, got one made by Atlas Metal Spinning years ago and still use today. Heats fast and evenly, cooks perfectly, allowing of course for operator error, and cleans up easily. My only complaint about woks is wok lids. It seems to me that the lid should double as a bowl for ingredients...chop veggies into it then dump into the wok. But the lids are all made with a handle that sticks up. I have thought about taking an appropriately sized stainless steel bowl and hammering a recess into the center of its flat bottom and having a piece of steel welded or brazed across the recess so the lid would sit flat on my counter when upside down. But, yeah, carbon steel. Woks were developed as a cheap way to cook...heating fast and cooking in oil uses less fuel, and clean-up is minimal. Water in the wok, let boil, scrub with that weird looking bamboo thingy that came with it, dump and dry over your heat source until dry and wipe with an oiled cloth. They're made to be easy and efficient.