Man's oldest cooking metal - cast iron. It's a classic because you can literally buy it for life (and your kids' lives and their kids' lives)
Perfect for getting that sear just right on your steak or making sure your fish doesn't fall between the grates.
You can use it as a warming tray as well - get its temp up straight on the grates, then throw it on a side table and use it to hold the burgers that just came off.
We bring ours inside on the weekends and use it on our glass-top stove for pancakes.