Pirates of the Caribbean: At Worlds End (2006)
There you have it, the most expensive movie of all time. And also one of the worst on the list. A muddled, nonsensical, suspenseless, self-indulgent, overlong, and pointless film. It looks nice though.
Cost: $316.6m
Why, the biggest movie budget ever (as estimated by both Wikipedia and Box Office Mojo among others) was needed for an ambitious production of an ambitious film. The production notes reflect the movies huge logistical and financial scale: filming on the open ocean and in several exotic locations including St. Vincent, Dominica, the Exumas, Grand Bahama Island as well as California and Hawaii; constructing giant water tanks; designing hugely complex action scenes; and, predictably, an extensive use of CGI effects.