@serialnamechanger27 With Charlie and the chocolate factory:
In the book, Wonka's main rival is "Flickelgruber", but Slugworth is mentioned as one of "the other rotten chocolate makers". The whole subplot of Slugworth asking the winning children to give him a Gobstopper is not in the book, neither is the contract, or Wonka yelling at Charlie in his office. After the elevator has flown through the roof, they have a look at the other children going home, now drastically altered.
Re: the fizzy lifting drinks: they are described in the book, but nobody drinks them. There's a whole chapter in the book where they rush past various rooms, including the lickable wallpaper, cows that give chocolate milk, hot ice creams for cold days, and so on. "Why can't we see them?" Veruca wailed. "Why do we have to keep rushing past these lovely rooms?"
There are some brilliant descriptions in the book, which didn't appear in the film. Wonka on "hair toffee": "I've got it too strong, it works too well. I tried it on an Oompa-Loompa, and immediately a huge black beard started shooting out of his chin, and soon it was trailing all over the floor in a thick hairy carpet, and it was growing faster than we could cut it! In the end we had to use a lawn-mower to keep it in check! But I'll get it right soon, and when I do, there will be no excuse for little boys and girls going around with bald heads!"