Orion the Hunter may be the most recognizable constellation, visible from both hemispheres. It's best in winter from the north and summer from the south.
The constellation Triangulum lies close to overhead in northern skies on December evenings. It contains the Triangulum galaxy, a gorgeous pinwheeling spiral.
Cetus the Whale is a huge constellation that swims in a sea of stars near constellations named for a river and fish. And it contains a wonderful variable star.
Fornax the Furnace appears as a few dim stars to the unaided eye but harbors galaxies from one orbiting the Milky Way to some at the edge of the universe.
The constellation Andromeda the Chained Lady is most famous for containing M31, the Andromeda galaxy, the closest large spiral galaxy to the Milky Way.
Pegasus the Flying Horse is the 7th largest constellation. It dominates fall skies in the Northern Hemisphere and has a famous asterism called the Great Square.
Tucana the Toucan is a constellation in the Southern Hemisphere that's a cinch to spot. Just look for our little satellite galaxy: the Small Magellanic Cloud.
Auriga the Charioteer is a north circumpolar constellation best viewed on autumn and winter evenings. Its star Capella is the 6th brightest star in the sky.