1. Pacific Ocean: The largest and deepest ocean, covering over 30% of the Earth's surface.

2. Atlantic Ocean: The second largest ocean, covering about 20% of the Earth's surface.

3. Indian Ocean: The third largest ocean, covering about 15% of the Earth's surface.

4. Southern Ocean: Surrounding Antarctica, this ocean is formed by the confluence of the Atlantic, Indian, and Pacific Oceans. It's often considered the fourth largest but doesn't always appear on lists due to its recent definition.

5. Arctic Ocean: The smallest and shallowest of the world's oceans, located around the North Pole.