Starting off with one of my favorites, and for good reason... the Waldameer Whacky Shack is one of the best classic darkrides anywhere. Beginning with the memorable recording that repeats over and over in the queue (Hello, Earthlings!), almost every scene, designed by the late Bill Tracy, is original to the ride. The playful façade is a classic example of the creativity that Bill Tracy brought to the table in the design of dark attractions; it's altogether original, yet the twirling eyes somehow hint at the spooks that are found inside. The Whacky Shack will also turn 50 years old in 2020.
I feel very fortunate to have been able to have visited both of the best remaining Bill Tracy darkrides in the country today, the aforementioned Whacky Shack and this, Trimper's Haunted House. As far as darkrides go, this one uses an interesting mix of visual tricks and purposely scary scenes. It is a ride that has been constantly evolving over the years, but it has maintained the majority of its Tracy stunts remarkably well. Like the Whacky Shack, Trimper's Haunted House is two stories, but the Haunted House has a very long track length that gives the ride a five minute run time.
Compared to the two examples above, Knoebels' Haunted Mansion and Black Diamond have relatively un-inspired facades. However, the content that is found inside both of these attractions is far from mundane. Both were designed in-house by the park, and both form two sides of the equation for a perfect darkride: Haunted Mansion specializes in many theatrical techniques, with expert use of diversion and lighting, while Black Diamond is a heavily themed and detailed (I probably rode it five times this year, and I noticed some new effects every time) hybrid darkride/roller coaster. Both are stellar and among my all-time favorite park rides.
Laffland at Sylvan Beach Amusement Park in New York is a little off-the-beaten-path, but the trip is worth it. This is the textbook example of a classic Pretzel darkride - the cars even still have those big pretzel-shaped counterweights on the front. After seeing the slightly run-down appearance of the rest of the park when I visited in 2017, I wasn't expecting a whole lot, but boy was I surprised; Laffland is chock full of vintage stunts, most all of them in perfect operating condition. There's even a large assortment of car-activated "noise makers" that add the most down-home of sound effects. 60-some years old, Laffland is a gem that I can't recommend enough.
Finishing off this list is one of my local rides, the Devil's Den at Conneaut Lake Park. Like Laffland, it's a Pretzel creation, except this ride runs solely on gravity, with a chain lift and small dip utilized for the cars to gain momentum. The stunts inside are mostly modern, but they are all hand-built tableaus that are very detailed and thought-out, especially considering how fast your car whips around the turns!
Happy Halloween!