Sintra (PVC) signs are a great option for durable indoor / outdoor signage. We print directly to the material for a clean crisp look.
DiBond is a great material. The faces are aluminum with a PVC core. White or Brushed Aluminum finishes. These can be direct printed, cut, or have vinyl applied.
Acrylic is a versitile material. Great for cut letters & logos, as well as for backlit prints.