William Shakespeare often used extended metaphors in his plays. For example, from "As You Like It": "All the world's a stage, and all the men and women merely players; They have their exits and their entrances; And one man in his time plays many parts."
Another example from Shakespeare is found in "Romeo and Juliet": "Within the infant rind of this small flower, poison hath residence and medicine power. In man as well as herbs, grace and rude will; And where the worser is predominant, Full soon the canker death eats up that plant."
One of the most-quoted examples in poetry is from Robert Frost's "The Road Not Taken," where on the surface he is trying to decide which way to turn at a fork in the road, but, of course, the meaning extends to life itself. "Two roads diverged in a wood, and I--I took the one less traveled by, And that has made all the difference."
Extended metaphor can be continued throughout an entire literary work, and many novels are seen as one long extended metaphor. "The Strange Case of Dr. Jekyll and Mr. Hyde," by Robert Louis Stevenson, is seen by many as an extended metaphor of man against himself. Dr. Jekyll is good and kind, and in trying to hide his malicious side, he is overcome by it in the end.
Television shows use extended metaphor as well. On the television show "House," Dr. Gregory House sometimes jokes about his fondness for metaphors. An example of an extended type: "The tumor is Al-Qaeda. We went in and wiped it out, but it had already sent out a splinter cell--a small team of low-level terrorists quietly living in some suburb of Buffalo, waiting to kill us all." See the Resources section for several other metaphors from Dr. House.
Sometimes lyricists create an entire song as an extended metaphor. The Eagles' "Hotel California" is a good example, where the Hotel becomes a metaphor for the shallow and self-absorbed 1970s lifestyle. "Her mind is Tiffany twisted, she got the Mercedes Bends. She got a lot of pretty pretty boys that she calls friends." As in the tacky "Mirrors on the ceiling, and pink champagne on ice," the song emphasizes the tawdriness which eventually the protagonist finds himself trapped in.