What is the best piping to use to replace older pipe?

If you ask 5 different plumbers, you may get 5 different answers. Over time, galvanized steel, copper and PVC have been used. Currently, galvanized pipe is not used for standard household plumbing. Copper has lost popularity due to its cost. PVC is still used for drains but seldom for higher pressure supply lines. The most popular product in use today is a called “Pex”. It is a very reliable polymer product which is relatively inexpensive, has fewer joints to leak, and does not corrode as it is resistant to hard water and electrolysis.