L&W Supply in San Francisco is highly praised for its excellent selection of drywall and soundproofing materials, including quiet rock, RC channels, metal studs, and green glue. Customers highlight the outstanding customer service, especially mentioning staff members like Eric and Red for their professionalism and assistance. The general manager, Mike, also receives positive remarks for his friendly approach. Overall, L&W Supply is regarded as the best place for drywall supplies and related materials, making it a top choice for customers.