The best optical illusions

The best optical illusions is a screamer video uploaded to YouTube on July 21, 2009, by Bryson Smith (thenexthotthing).

The video, of course, starts with the blue text challenging the viewer to read "Can you find all 3 faces?" Afterwards, the video proceeds to show six images depicting optical illusions, such as:

A young woman looking away with the nose and mustache visible.
A scintillating grid.
The "I love Paris in the springtime" rectangle with two thes.
Machu Picchu, with the photo tilted 90 degrees counterclockwise, resembling a human face.
A fisherman trying to catch a big fish in a canoe or in a big bird`s mouth taken from The Upside-Downs of Little Lady Lovekins and Old Man Muffaroo.
The Terrace by David Macdonald.

However, after an array of images until the last one featuring the Stroop effect, a close up image of Regan MacNeil from The Exorcist pops up accompanied by the same scream from The Maze and other Winterrowd games.