One of the most used items in my kitchen is the Uncoated Commercial Sheet Pan (about $10-15) like this one...
- They're larger and sturdier than any home cookie sheet you can buy. They rarely warp under high heat and you can fit a full 12 cookies on them.
- Because I buy only the uncoated kind, cookies don't burn as easily. Most people think that nonstick surfaces are better but they actually enhance browning (aka burning if you're not careful).
- Again, because they're uncoated, I can scrub away baked-on gunk with abrasive cleaning pads like Brillo or SOS. Try that with a coated pan and all you'll succeed in doing is ruining it and sometimes, the stuff is just permanently baked on.
- They make great trays for prepping ingredients, freezing items loose for later storage in a zip-top bag, drying chocolates, and carrying things around the kitchen.
Incidentally, Walmart usually has these in stock in the store, so you don't even have to wait for it to ship.