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.
Best Known for the Fanservice: Most people remember this as "the movie where the Cosby kid gets naked". It's unfortunate since the film is an excellent horror/mystery with great performances by everyone involved, including Mickey Rourke and Robert DeNiro.
Johnny Favourite was a hedonistic occultist who made a Deal with the Devil for fame and fortune. To back out of his contract with Satan, he assumed a new identity and life by performing a black magic ritual which involved cutting out a young man's heart and eating it to steal his soul. When private eye Harold Angel is hired by the Devil to find Favourite, he starts killing off every one of his old allies whom Angel speaks to, including shooting someone through the eye, boiling someone to death in a frying machine, and cutting out another person's heart. He knowingly has sex with his daughter Epiphany Proudfoot without her knowledge of their relation. Later, he rapes her to death by shoving a loaded gun into her vagina before firing it, leaving her baby boy an orphan.
Louis Cyphre is a mysterious client who eventually reveals himself to be none other than Mephistopheles himself. He makes contracts with mortals in exchange for their souls so he can take them to Hell, or sometimes devour them. After Johnny Favourite escapes out of the deal he made with the Devil, he hires Harold Angel to bring Johnny back to him. He arranges for all of Favourite's old allies to be gruesomely murdered in the process. He claims to live by "an eye for an eye"-type honor, but eventually shows his hypocrisy when he also causes the death of the innocent Epiphany in about the most horrifying way possible and murders his human attorney by staging an accident. He freely admits that he positively revels in all the death he sees occuring to humanity.
Crosses the Line Twice: When Harry and Cyphre meet in the church, Harry swears several times, but Cyphre of all people! admonishes him, saying "We're in a church!" Judging by his bemused grin, it's hinted he enjoyed it, however.
Fridge Brilliance: The scene where Louis offers Harry an egg. Because in hindsight, you realize that Satan just offered Johnny his soul back, and he turned it down. Doubles as Fridge Horror when you realize that the Devil is gleefully consuming souls.
Narm: YMMV, but the "who was the booooyyy?!" bit does slip into Seven-ish territory, even though the whole ending scene is horrifying.
Though the part in said scene where Epiphany's child's eyes (and Robert de Niro's) turn red is also a little ridiculous, if only because the special effects used are pretty corny.
Rewatch Bonus: This is a very sad movie from the beginning if you know where it's going.