Relating to Animal Farm, what corrupts people more: money, material items or power?

In Animal Farm, power corrupts far more than money or material goods: in fact, we could group money and material goods together as the same, but for the sake of this exercise we will keep them distinct. Money we will apply to humans and material goods to animals.

Orwell shows through Molly, the horse who doesn't take well to life after the animals take over the farm, that materialism isn't necessarily evil. Molly doesn't...

In Animal Farm, power corrupts far more than money or material goods: in fact, we could group money and material goods together as the same, but for the sake of this exercise we will keep them distinct. Money we will apply to humans and material goods to animals.

Orwell shows through Molly, the horse who doesn't take well to life after the animals take over the farm, that materialism isn't necessarily evil. Molly doesn't want to work hard, and she misses the red ribbons that were once braided into her mane. She likes to sleep late, and she likes material goods, such as sugar, which she can't get under the new regime. Eventually, she flees the farm and goes back to the humans. This may make the other animals unhappy, but Orwell shows it does them no real harm and does Molly no real harm. Her love of material things might not make her the most enlightened thinker or be much of a help to anyone, but while depicted as silly, she's certainly not an evil character.

Farmer Jones wants money—to make a profit on the farm—and that drives him to work the animals hard, but Orwell is at pains to show it is his alcoholism and neglect that leads to the problems for the animals that cause the revolt. If Jones had never taken to drink, the animals might have rocked along forever under his regime.

But Napoleon's lust for power and his inability to allow anyone to challenge him does corrupt him and the pigs who follow him. He treats the animals cruelly for no reason other than to terrorize them so that he can maintain total control. To be corrupted means to be changed into something worse than you once were. It means to become evil. Napoleon no doubt had the seeds of evil in him, but when he acquired power, the seeds of evil grew into evil itself. This is symbolized by the way he turns into a human, drinking alcohol, sleeping in a bed and walking on two legs: ironically, he is harsher towards the animals than their prior owners.