8. Watchmen http://www.youtube.com/watch?v=d8kQImYo3Ww I'm sure plenty will disagree with this, but I thought the ending to Zack Snyder's Watchmen made so much more sense than what appeared in Alan Moore's graphic novel. Moore's version has Ozymandias bio-engineer a gigantic squid that massacres New York City and gives the humans the impetus they need to band together and stop trying to destroy each other. The idea of giving mankind a common enemy is pretty clever, but the notion of a giant freaking squid is just too damn weird, even if the point ultimately is that the adversary has to be a sufficiently grotesque "other" in order to bind humanity together. In Snyder's movie, this is changed to Ozymandias tricking Dr. Manhattan into becoming a nuclear bomb, a far cleaner narrative through-line in my opinion. Snyder himself considered using the squid before realising that you would need about half an hour to explain quite what on Earth was going on in an already super-long film. Besides, a CGI squid would almost definitely look awful, and would only compound the likely notion that mainstream audiences not acquainted with the source material would outright reject its out-of-nowhere strangeness. Many fans criticised Snyder for his decision, but cinematically speaking, it was absolutely the right one.