Aluminum and steel are the two most common professionally installed gutter materials. The one that is best depends on your situation.
Major plusses for aluminum gutters are that they’re relatively inexpensive and will never rust. Steel gutters are sturdier, but this isn’t necessarily an issue unless you’ll be leaning ladders against the house for access to the roof or live where high winds, trees, or other factors may cause wear and tear. Most homeowners opt for seamless aluminum.
One gutter installer who has been in the seamless gutter business for 15 years in Fargo, North Dakota, says, “In this area, we're probably 90% seamless gutters. I like aluminum because downspouts get plugged and you get water sitting in the gutter, but you don’t have to worry about rust. Steel will rust out after a time.”
He adds, ”I've laid them side by side on the ground and dropped a screwdriver on them and the steel dents just as easily [as aluminum]. Every once in a while, we use steel to match a color that only steel comes in. Steel is a little bit cheaper.” The price range for steel tends to run from $2.50 to $4 per foot. Aluminum gutters cost from $5 to $9 per lineal foot, installed. The metal is available in more than one thickness—opt for the thickest (.032 gauge).
Both aluminum and steel are made in a broad palette of colors. Alcoa produces a faux copper gutter that, at about $9 per lineal foot, installed, offers the look of copper at about half the price of the real thing.
Copper rain gutters. Most people agree that copper makes the ultimate gutter. Handsome, with a natural patina that ages to a verdigris color, it doesn’t require any finish. It will last as long as the house because it doesn’t rust.
Copper gutters are installed either as half-round sectional systems or in the same profiles as seamless aluminum gutters. Sectional systems, fabricated by metal shops and soldered at the joints, are very expensive. Prices fluctuate with the value of copper, but expect to pay $15 to $20 per lineal foot. Seamless copper gutters, typically made from 16-ounce copper, are slightly less—from $13 to $18 per lineal foot, installed. At these values, copper gutters have become a target for thieves in some cities.
For restoration purists, lead-coated copper is also available in some areas. This will last over 75 years. A 5-inch sectional system runs over $20 per lineal foot, installed.
Stainless steel gutters. Though seldom used, stainless steel is another high-end custom material. Like copper, it doesn’t rust and will last as long as the house. It is a little too glitzy for most homeowners, particularly at an installed cost of about $20 per lineal foot. 
