There a many types of roofs:

• Slate. Natural quarried stone or engineered slate made from composite plastics
• Cedar Shakes. Natural Cedar Wood as well as asphalt designer shakes that closely mimic the appearance of natural wood shake
• Sheet Metal. Corrugated, flat and flat with ridge sheet metal.
• Asphalt. Asphalt construction ranging from typical flat shingles to a wide variety of architectural designs
• Flat. Peel and stick (can be color matched), cold-pressed glue down (black and white), EPDM rubber roof, heat-welded torch down (black and white) and clay tiles

Each manufacturer touts their own specific benefits and bells and whistles but in the important matters they are very similar. The most important choice is the underlayment. The options are ice and water shield, felt/tar paper (organic)/synthetic deck covering, and ridge venting.