4. Spawn
1997's Spawn stands as not only one of the worst comic book adaptations of all time, but also one of the most disappointing, given the gritty, adult potential of the series to be a grown-up, R-rated smash hit. Instead, we got campy theatrics, terrible acting, and a plot that's totally forgettable. It's no surprise that nobody's wanted to really touch the franchise again since, though the comic's creator, Todd Macfarlane, is attempting to get a reboot off the ground, and has some pretty zany ideas of how to go about it as well. Macfarlane wants to make it super low-budget, cast an unknown actor, and then not have Spawn speak for the entirety of the film, comparing Spawn's presence to how Jaws and the Xenomorph were unveiled in Jaws and Alien. It's an ambitious, but more importantly misguided idea - studio executives have so far seemingly balked at the notion, and even if the thing gets made, we imagine it'll be straight-to-video given the character's low standing on the superhero totem pole.