Days of Future Past: Part 1 - S1-E11
Trivia: After Bishop travels into the past, he hears one kid telling another that they will be playing the new Punisher game "Assassin." When the Punisher was first being developed, he was originally going to be called The Assassin.
Trivia: When Dorothy is walking into the pub to meet Gary, she walks past a brewery sign. The owners are Newton and Ridley, the brewery from Coronation Street.
Curiouser & Curiouser - S2-E22
Trivia: All the sets in the dream sequence, particularly Nick's loft, are filled with props referencing Lewis Carroll's Alice in Wonderland books. They include white rabbits, flamingos, walruses, a squeaky-toy caterpillar - even a half-eaten piece of cake in Nick's fridge. The episode also has several background extras in Wonderland-style costumes, and numerous other references to the books, such as Nick literally falling through the looking glass at the end.
The Tale of the Dream Girl - S3-E10
Trivia: It's widely speculated that this episode inspired the movie "The Sixth Sense," although the movie's director, M. Night Shyamalan, claims that he has never watched it.
Trivia: The series was cancelled before the kids were able to learn who Ghostwriter was in his previous life. Producer Kermit Frazier revealed in 2010 that Ghostwriter was a runaway slave during the Civil War who was hunted down and killed while teaching other runaway slaves to read in the woods, and that his soul became trapped in the book that he emerged from Jamal's basement.
The Last Shout: Part 1 - S3-E7
Trivia: In this episode, Patsy makes reference to "when I was a Bond girl." Joanna Lumley played a Bond girl in the 1969 film "On Her Majesty's Secret Service."
Trivia: R.D. Wingfield, author of the book "Frost" on which the series is based, hated the show.