Prometheus

One character in Prometheus saw this alien parasite and immediately tried to pet it.  He died.

Prometheus is a visually stunning film in which unlikeable characters say dumb things to each other and constantly have stupid fights for no reason.

You already saw the good bits in Alien, sociopathic android and all. Mixed with these are a bunch of shitty subplots about romance, sinister corporate motives, and the struggle to maintain religious faith. Seriously, Ridley Scott has taken humanity's search for meaning in the universe and turned it into a fucking snooze-fest.

The only real take-away is that if you see a cave on an alien planet that looks like an H. R. Giger painting, DON'T GO IN THERE. Also, I lost count of the number of alien body parts that looked like moist, threatening vaginas with teeth.

Oh, and there's also a scene in which a woman programs a robotic medical pod to give her an abortion, but then the fetus turns out to be a squid. Because we've all been dying to see that in 3-D.