8. Cowboys & Aliens
Cowboys & Aliens is based on the 2006 graphic novel of the same name created by Scott Mitchell Rosenberg, revolving around a mysterious outlaw suffering from amnesia (Daniel Craig), a wealthy cattle rancher (Harrison Ford), and a mysterious traveler (Olivia Wilde) who are forced to team up to save a town being attacked and abducted by aliens. It's a hilarious idea for a film regardless of where it came from - turning the classic game of Cowboys & Indians on its head - yet the final result was such a limp, tepid disappointment, all the more so because it came from Jon "Iron Man" Favreau. Despite assembling a top-notch cast and a sky-high budget of $163 million, the film is one of the most oddly boring action movies in recent years, and as a result it only made $174 million at the box office. Compounding things is the overly self-serious tone; no film with a title this ludicrous should be anything but tongue-in-cheek, and in the unlikely event that any studio ever agrees to reboot it, the emphasis this time needs to be on silliness and fun.