Defictionalized

the Nikki Heat series of books by "Richard Castle"

Idiocracy has two. One is the energy drink Brawndo.
There is also the video game Ow My Balls, which is clearly based on the show within the movie.

Square tomatoes!
"You can taste the symmetry!"

One of the Postal Dude's tasks for Thursday is to buy a Krotchy doll. Real Krotchy dolls are available from Running With Scissors, the game company behind the Postal franchise.

There is a blood orange drink based on the beverage in the tv show.

There is Duff beer in Mexico and a Duff energy drink in the US.

Cheesy Poofs

Wonka candy, of course.