Jacques Cousteau) would argue that the Oceanic White Tip is the most dangerous.) Bulls are the most aggressive sharks there are, and are credited with the most attacks on humans near shore. Despite not being the most vicious, the great white is, most likely, the largest meat eating shark alive today, but its ancestor the Megalodon was even bigger! How big? Average size is theorized to be around 67 ft in length and 103 metric tons in weight, (of course they could have been bigger.) That's big enough to swallow a Great White shark whole. Just imagine if that shark was around today! Swimming, sailing, surfing, anything done in the ocean, would probably be incredibly dangerous.
Now what exactly did this monster eat? There is evidence that megalodon preyed upon a variety of marine animals including sperm whales, bowhead whales, dolphins, porpoises and even giant sea turtles. Due to its size, megalodon would have fed primarily on large animals, and whales were likely an important food source. According to wiki many whale bones have been found with clear signs of large bite marks (deep gashes) made by the teeth that match those of C. megalodon, and various excavations have revealed C. megalodon teeth lying close to the chewed remains of whales, and sometimes even embedded in them.
Thank goodness they're extinct.