7. Watchmen
Various studios had been trying to get a movie adaptation of Alan Moore's classic graphic novel Watchmen off the ground for years, and in 2009, it was finally released to solid acclaim, though extremely disappointing financials. How, then, is Watchmen ambitious? Where to begin; Moore's source material remains one of the most acclaimed graphic novels in history, praised for its dark interpretation of the superhero myth, creating a world in which the heroes are more realistic and human, not always doing what's right. Furthermore, he rooted them in a very deliberate sense of time and place, an alternate history where the appearance of this gang of superheroes influences various political and world events throughout the 20th century. It's not exactly run of the mill material for studios used to dealing with Peter Parker, Clark Kent and Bruce Wayne, but Warner Bros. took the gamble and allowed Zack Snyder to produce a $130m, R-rated, 162-minute superhero opus that stands as a staggering achievement. Given the density of the source material, it's amazing that Snyder was able to fit so much into the runtime, and though fans remain divided over whether it was necessary to alter the ending (which in the novel features the invasion of a giant squid on Earth), it's hard to argue against the sheer level of gall to even try and adapt it, and then to do it (largely) so well.