Many people think Polaris is the brightest star, but it's only 48th in brightness. Still, Polaris is famous because the entire northern sky wheels around it.
Alphard is the "heart" and brightest star in the constellation Hydra the Water Snake, and it represents a welcome sign of spring for the Northern Hemisphere.
Sirius is the brightest star as seen from Earth and is visible from both hemispheres. It lies just 8.6 light-years away, in the constellation Canis Major.