@FurryKittens: Basically, everyone who says it's Hamlet with lions is only reading it at its most superficial level: the basic plots follow parallel beats (usurping uncle, reluctant prince, exile/return and bloody reckoning driven by a ghostly father), but Hamlet spends most of the play in existential introspection—it's a thinking story, with one of the interpretive hinges being whether Hamlet is "playing the fool" or is actually going mad. Most of the story revolves around his struggle to convince himself to avenge his father, and is largely a cautionary tale about the destructive cycle of revenge. (The play ends with most principal characters dead, directly and indirectly, from Hamlet's pursuit of that vengeance.) It's been said that Hamlet is the only Shakespearean character who's bigger than the play itself, because of his sheer psychological complexity.

Compare The Lion King, in which Simba is exiled at the start of the story after being fooled into thinking he was responsible for the stampede: he isn't even considering revenge, and after his rescue by Timon and Pumbaa, he basically tries to forget about his old life. Even when Nala says Pride Rock has gone to pot, it's Mufasa's vision that finally convinces him to fulfil his responsibilities—not framed as avenging his death, but to rise to his duty as heir to the throne. There's no equivalent of Polonius, Laertes, or Fortinbras, and thus no revenge thread—Scar only cops to the deed during the final fight, and his overthrow is framed as a clear-cut restoration of justice.

Thus while both stories hit on similar plot points, their core morals are completely different. The easiest way to disprove The Lion King is a Hamlet riff is that it does not follow a tragic structure. ;p