These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Special honors go to "The Girl in Byakkoya" though. The crazy juxtaposition of acoustic and electronica make for a song that's memorable, enjoyable and strangely romantic.
Ear Worm: "Mediational Field", the opening theme, the ending arrangement, and "The Girl in Byakoya".
The aforementioned viewers would argue that Chiba ending up with Tokita is equally trite and cliché for its wish fulfillment for male audiences.
Fridge Brilliance: Chiba's first foray into the Dream World is interrupted by her falling in real life. Also known as: myoclonic jerk.
Harsher in Hindsight: All the talk about Konakawa's incomplete film. Paprika was Satoshi Kon's last completed project; he died partway through making another film called, coincidentally enough, The Dream Machine.
High Octane Nightmare Fuel: The mad dream parade, the scene where Dr. Osanai peels off Paprika's skin, the laughing doll (Brrrrr...), and (the buzzing sound that appears when the doll is first shown in what appears to be the real world, or when Paprika sees Tokita asleep.
The parade does this especially well, considering it's an Amazing Technicolor Population of Grotesque Cute with an upbeat, cheery-sounding Ear Worm theme. There's something to be said of how the film makes terrifying a somersaulting frog whipping out drumsticks.
Subbing vs. Dubbing: A rare case where both sides have merits. The first meltdown dialogue comes off like a poorly translated metaphor in the subbed version, while the dubbed version makes it clear that the speaker's lost his mind. Interestingly, the dubbing goes for the spirit of the script rather than the translation, leading to entirely different but still effective dialogue.