The Fermi Science Playoffs celebrate 10 years of the Fermi Gamma-ray Space Telescope’s exploration of the high-energy universe. Surviving all early rounds of voting, these two finalists in the competion square off at last. Digital illustrations from a list of 16 of Fermi’s top scientific discoveries, they represent the competition’s two top seeds, defeating 12th seed New Clues to Dark Matter and 14th seed Starquakes in Magnetar Storm in the semifinal round. On the left are unprecedented, unpredicted, 25,000 light-year tall Gamma-ray Bubbles above and below the plane of our Milky Way galaxy. On the right, violently merging Neutron Stars Collide to create the first gamma-ray detected gravitational wave event. Pick one now and cast your vote here to crown the most popular science result from Fermi’s first decade.