The Discovery Channel is in hot Pliocene water over their "documentary" Megalodon: The Monster Shark that Lives, which asserts that the Megalodon is still living in our contemporary seas. Even nerd guru Wil Wheaton unleashed his anger! Massive fail, Discovery.
Megalodon is most assuredly extinct. Denying that is messed up, because this extraordinary animal was way more interesting in real life than any fabrication Discovery could hope to throw together. Reaching lengths of 60 feet and weighing 100 tons, Megalodon was easily the biggest predator ever to grace the seas — check out how it dominates this scale chart. It also had the most powerful bite of any animal ever, about 10 times what its closest living relative, the great whites, exert on their prey. And though it is gone forever, we are not separated from this glorious beast by much. The last Megalodons died out only two million years ago, which is basically yesterday on the geological time scale.