Not because of the still awesome transformation scenes or the gore or the chases or any of that nonsense.
It was Jack, played by Griffin Dunne, who scared me and gave me nightmares I can still remember! The idea of the bloody, decaying corpse of your best friend stalking you and telling you to kill yourself gave me the heebie jeebies. Still does. This is a very strange movie in many ways. It is funny, as you would expect from John Landis. It is gory, as a Werewolf movie should be. It also has so many surreal touches, such as the dream sequence involving Nazi inbred cannibal people (what the fuck?) and the extended porno theatre setting. In fact, David meeting his victims in the porno is one of my favorite scenes, and may have made me scared to go to the movies for a while as a child (of course, my parents were not taking me to pornos, but they did take me to see films like Reds and Yentl which bored the shit out of me and probably led to my overactive imagination. I actually once threw a fit in the theater because I was convinced Zombies were going to come get us. My mom had to take me out of there. It got me out of seeing Fiddler on the Roof.)
Now enjoy David Naughton singing "Makin it!"
He was either the worst lip syncher in the world or this is a terrible dub.