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.
Nightmare Fuel: What happens to the Levite's concubine in chapter 19. The Levite is entertaining a guest at his home when men of the city surround the house and demand that he hand the man over, "that we may know him carnally." The Levite gives them his concubine instead. They gang-rape her to death and leave her body on the threshold. Particular a case of Values Dissonance as at first he offers them his daughter as well, although the only one he actually hands over is the concubine, making her one of the earliest and saddest examples in literature of a Disposable Sex Worker.
One-Scene Wonder: Shamgar gets only one verse to his name, which adds that he killed 600 Philistines with an ox-goad (a stick used as a cattle prod.)
Squick: King Eglon's death. So fat his body swallows up the entire sword he's stabbed with, and poops his pants in the process.
What an Idiot: Jephthah foolishly vowing to God that he will sacrifice the first living thing that comes out of his house if he wins a battle. After God already told him he would win. And the living thing turned out to be his daughter.
Samson never seemed to pick up that every time he told Delilah a false way to defeat him, a pack of Philistines would be in his home the next day trying the exact same method.