How about Kapton tape, painters tape, Ultrabase... IKEA mirrors? Over the years, the advice has changed. We just updated our guide to help you find a suitable build plate.

For most new printer users, I'd wager it's the print bed that came with the printer and nothing else. Print beds today are pretty well tuned to the majority of materials, but are still consumable. You'll need to replace it at some point in its life, but have the manufacturer defaults gotten so good there's no room to experiment with others? Are you still using the bed that came with your printer, or have you replaced it?