Backpacking -> titanium if possible, aluminum next, then steel. Be aware that stuff will stick to all, especially if using the uneven heat of a campfire. Most of my backpacking / hiking cooking centers around boiling water. because of this, if cost is an issue any metal container will work.
Any form of camping where I don't have to carry the cookware -> cast iron, cast iron, and last choice...cast iron. I've used all other types over the yars but for ease of both cooking and cleanup, cast iron wins. It's durable, long lasting and typically inexpensive.
My 2 cents anyhow. Cheers.