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.
YMMV: The Fisher King
Hilariousin Hindsight: Dan Futterman appears as one of the teen punks who antagonizes Parry and Jack, eventually beating up Parry so badly that he gets put into a coma. Just a few years later, he would go on to play the loving son of Robin Williams' character in The Birdcage.
Moral Event Horizon: The two teen thugs that try to light Jack on fire just for being in the wrong place at the wrong time. They later beat the hell out of Parry for the same reason and put him in the hospital.
Nightmare Fuel: The Red Knight. The fact it's a hallucination does nothing to take away from how terrifying it is. The film does a good job of showing just how terrifying the thing is through Parry's eyes. Especially at the end when it chases Parry through the city overlapped with Parry's memories of his wife being murdered right in front of him.
His flashbacks to his wife's murder are also horrifying. Particularly the fact that when she was shot her blood and brains splattered in his face. Is it any wonder the poor guy went insane after that?