Kate,
I had to work at the Goodnight Gorilla thing. And ds wanted to hear it about 50 times in a row.
He liked the story when I referred to the zookeeper as the daddy and his wife as the mommy. So I started out with "The daddy says good night gorilla and the gorilla takes his keys." And then I described some items in the gorilla cage. "The gorilla climbs out of his cage and follows the daddy with the flashlight." "Then the daddy says good night elephant, and the gorilla lets him out of the cage with the pink (whatever) key." Etc. "The armadillo, giraffe, hyena, lion, elephant, gorilla, and the mouse with the banana follow the daddy into the house." Basically, I just keep listing the animals and what they're doing.
If ds wants to hear the book AGAIN, we follow the mouse through the book. Or we notice the color of each key. Or the stuffed animal in each animal's cage. I also noticed that you can follow the pink balloon--it's on every page. There are a lot of details in the book that I really wish I didn't know about.
It's not my personal favorite book.