As a writer and a student of English, I found these pretty funny. They're actual metaphors and analogies used in high school English essays. You might have seen an email like this, but I'm posting it here because it's hilarious!
Her vocabulary was as bad as like...whatever.
His thoughts tumbled in his head, making and breaking alliances like underpants in a dryer without Cling Free.
She grew on him like she was a colony of E. Coli, and he was a room-temperature Canadian beef.
Her hair glistened in the rain like a nose hair after a sneeze.
The little boat gently drifted across the pond exactly the way a bowling ball wouldn't. (One of my favorites!

)
The plan was simple, like my brother-in-law Phil. But unlike Phil, this plan just might work.
He fell for her like his heart was a mob informant, and she was the East River.
The young fighter had a hungry look, the kind you get from not eating for awhile.
Her eyes were like two brown circles with big black dots in the center.
Her date was pleasant enough, but she knew that if her life was a movie, this guy would be buried in the credits as something like "Second Tall Man."
It was an American tradition, like fathers chasing kids around with power tools.
Gunshots rang out, as gunshots are wont to do.
"If a man does not keep pace with his companions, perhaps it is because he hears a different drummer."
--Henry David Thoreau
brains+brawn+beauty+personality=MacGyver