Impostor (2001)

Based on the 1953 Phillip K. Dick short story of the same name, Impostor (2001) tells the story of a future Earth at war with an alien race that uses androids that look like humans as bombs. It's 2039 and earth has barely survived an attack from a bunch of unseen aliens from Alpha Centauri. All of the big cities are covered in forcefields to protect them from attacks, so the aliens have conjured up a new scheme. They create exact replicas of already existing human beings, only they have little bombs in their hearts that explode the moment they come close enough to their target. Dubbed "Replicants," these creatures have all the real person's memories implanted in them, so they have no idea they're replicants. The only way anyone can figure it out is by slicing them open and checking the heart for the bomb. Spencer (Gary Sinise) is a weapons creator who the government arrests on suspicion of being a replicant. They want to slice and dice him just in case, but Spencer's one hundred percent sure he's one hundred percent human. He escapes but has to flee the government while figuring out what's really going on before they crack open his chest and see who was lying the whole time. Movies love to grab your attention right away, and nothing hooks us like some skin! To that rear end, Gary Sinise hits the shower as the opening credits roll. We see him shirtless as he sings along to some music while cleaning up, but don't get any real nudity. Boom. Mr. Man was heartbroken. If only he'd given us some Impostor posterior this one would've been a smash hit!