In one of my favorite Twilight Zone episodes, ("Perchance to Dream", Season 1) Hall (Richard Conte) finally seeks help from a psychiatrist after going without sleep for several days.
At the doctor's request, Hall describes several variations of his nightmares, including a recurring one at a surreal amusement park. It's the imagery of the amusement park that makes this episode stand out--footage of actual carnival rides combined with stylized sets that could only come from Hall's imagination.
"I was at an amusement park...it was the kind of place you see only in nightmares. Everything warped and twisted out of shape. But it was real, too. Very real." -Edward Hall
Step right up and see Maya the Cat Girl...perhaps a bit too exciting for our Mr. Hall?
After the show, Maya approaches Hall and lures him to the funhouse, a nightmarish gallery of bizarre exhibits.
Finally, Maya pressures Hall into riding the roller coaster, despite his protests.
Maya seems to be enjoying herself!
Hall, not so much...
I won't reveal the ending, other than to say it is terrifying and comes with a twist.
This episode was written by genre author Charles Beaumont, based on his short story of the same name, which can be found in the collection "The Magic Man". Unfortunately Beaumont's entire body of work seems to be out of print as of this writing.
The episode can be found on DVD in the Twilight Zone: Season One (or, if you didn't want to invest in an entire season, it is available on a single-disc, 4-episode collection called The Twilight Zone: Volume 7.)