Some movie plots are incredibly complicated. Others incredibly simple. Some we're just not supposed to take seriously. Others? Needlessly complicated stuff happens, when the solution is sort of obvious. Now, in some cases, you can argue that the story would be weakened if they took the obvious route, and, in almost all of these cases, yes, you're right. In a lot of cases,the journey is more important than the destination. ...but let's be honest. You're here to laugh at some films, and who am I to delay that? With much ado, let's get started.
10. Alien
The Plot: Space truckers go to an alien planet, and Olivander accidentally impregnated by a xenomorph. No one at the time realizes that's what's happened, though. All they know is their friend has a giant spider-alien thing clamped on his face. Despite Ellen Ripley telling them it's against protocol to let the alien inside, their token robot crew mate lets them in anyway. Everyone but Ripley dies.
The Solution: I'd say don't break protocol, but Ash, the token robot teammate, intentionally let the alien in so he could study it, knowing full well most of the crew would die. He intentionally sabotaged the mission. He is the bad guy. Unavoidable conflict. The real solution to the problem is don't poke around a garden of alien eggs. If you watch the movie, you know John Hurt's character wanders around a field of alien eggs, pokes around them, leans in toward an egg as it hatches--he was begging to get attacked. If you're a space trucker, you should know better than to poke around weird things you don't understand. People in the Alien universe must have a weird fascination with alien eggs, though, since scientists do the same thing in Prometheus. Both films were directed by Ridley Scott. I wonder what he'd do in that situation.