Best screw material/coating for longevity of an indoor device?

Hi,

what are the best types of screws (material/plating-wise) for fastening a PCB to a thermoplastic casing, to achieve the best longevity/serviceability of a consumer electronics device that would be wall mounted indoors?

What are the most common types of screws found in consumer electronic devices?

Is the price premium of stainless steel over zinc plated worth it?

Thanks!