Never rusts or needs painting; should last 100 years in any climate. Available in seamless or sections, and in three weights: 16, 18, and 20 ounces. Seams should be soldered. Oxidizes to a matte brown in a matter of months, blue-green over decades. If you prefer gray gutters that don't leave green stains, select lead-coated or tin-zinc-plated copper.
Cost: About $11 to $18 per foot