The answer to 'best supply line' is that the best supply line for your plumbing needs depends on the specific application and materials in your home. Generally, flexible stainless steel or braided supply lines are considered the most durable and reliable options for most residential plumbing fixtures like sinks, toilets, and washing machines. These types of supply lines are less prone to leaks and kinks compared to traditional rigid copper or plastic supply lines.
Stainless steel supply lines are a popular choice as they are corrosion-resistant, flexible, and can withstand high water pressure. Braided supply lines, which have a stainless steel interior and a protective outer braid, also offer excellent durability and flexibility. Both of these options are easy to install and can help prevent costly water damage from leaks or burst pipes.