1. Mr. Microphone ad: When they first enter the city, Donkey says, "Hey, Good Looking! We'll be back for you later."
2. Car Commercials: As Shrek is trying to sneak his two animal friends into the Potion storage room at the Fairy Godmother's factory, Donkey says to Puss in Boots: "You want to get your fine Corinthian footwear out of my face?" That "fine Corinthian" reference comes from a old Chrysler Cordoba commercial, where Ricardo Montalban uses to enthuse about the "fine Corinthian leather" that was used to decorate this luxury car's interior. A similar reference is made by Ricardo Montalban himself in Spy Kids.
3. Cookie Commercials - When Donkey first spies the Fairy Godmother's cottage / factory complex, he says: "The Old Keebler Place? I ain't going in there!" This - of course - is a reference to the TV commercials that the United Biscuit Company runs for its Keebler Cookie brand. This series of ads were (and still are) built around the premise that all of Keebler's cookies are baked by elves who live in a hollow tree.