Refrigerator Water Line

Hi,
Is plastic or copper tubing best for the refrigerator water line --or should I use a braided steel one? Our refrigerator has a plastic water line coming up from the floor and I want to make sure this is the right one -- I keep reading conflicting things. Thanks.

I prefer the copper lines. Also if your water line happens to be on a saddle valve it should be replaced as well.

I use either copper or the braided stainless.

I don't like the 1/4" OD plastic. I've seen them split.