Paul Schrader's Hardcore (1979) tells the tale of a strictly religious midwest dad who heads out to the seedy streets of San Francisco and Los Angeles in order to find his daughter, who may have been kidnapped by pornographers and forced into the industry against her will. This leads him down a dark and sleazy path, especially since it becomes increasingly obvious that his daughter actually entered the porn industry of her own volition.
Needless to say, this leads to a lot of internal conflict, and George C. Scott acts the shit out of that internal conflict (as you would expect). However, several scenes come off as unintentionally humorous when viewed out of context (who am I kidding, even when they are viewed in context). George awkwardly auditions several male porn actors, throwing on a fake stache, a cheap wig, a gold chain, and a tie-dyed T-shirt in a failed attempt to appear sleazy and hip. It's not a failure of the movie necessarily; after all, a strictly religious midwestern dad would have a hard time coming up with a convincing disguise for a low rent sleazy porn producer circa late 70's. Myself, I would have probably bridged the gap between Huggy Bear and Penthouse founder Bob Guccione, but I am neither a father nor religious.