Alternative Character Interpretation: Holden is either a shining beacon of morality amongst all that was wrong with the 1950s, or a whiny prototype Emo Kid (and a rather hypocritical one at that) who refuses to let himself see anything good in the world, or someone who has good insights and potential but is weighed down by cynicism and bitterness, OR just one of the first examples of teenage disillusionment in a post-World War II world. Or you think he's telling you to kill pop-culture icons (see Loony Fan in the Trivia sec). It really depends on the reader.
Holden is either a spoiled brat, or a young person realistically acting out because of the grief of his younger brother dying.
Hilarious in Hindsight: Why is this book so frequently banned? Because it uses the word "Fuck"- during a scene in which Holden, discovering it scribbled where grade-schoolers can see it, tries to scrub it out so it can never offend anyone again. Considering how much Holden swears BEYOND "fuck," this is somewhat justified. However, this does miss the point, considering how iconic the book is.
The underage protagonist spending the entire novel smoking, drinking (when he can get served), hiring a prostitute (though he doesn't actually sleep with her), having a generally negative attitude AFTER being kicked out of school might also have something to do with why people ban it ...
The infamous passage in which Mr. Antolini strokes the forehead of a sleeping Holden. Even Holden himself is rather disturbed, fleeing Mr. Antolini's house right afterwards.
Antolini's inquiries about Holden's girlfriends and the fact that he calls Holden "handsome" as he wishes him goodnight could be read as flirtatious advances as well.
Carl Luce, who was said to be always grabbing guys' butts, and somehow seemed to know if anyone was gay. He was most likely a case of Anything That Moves.
Note that, for a long time in America, this could have been Truth in Television; spotting a gay man based on behavorial patterns (that is, by any way other than catching him having sex with a man) was seen as a surefire sign that you were gay. Gaydar was one of the main reasons so many people were expelled from Harvard in the 1920's, even if they were into women or Anything That Moves.
Holden refers to how attractive Stradlater is all the damn time, including calling him a "sexy bastard" at least twice (though, as noted on the main page, this is most likely the result of Have a Gay Old Time).
Hype Backlash: Considering its reputation as both one of the most controversial and most loved books in history, it has lead to quite a few people being a little underwhelmed when they read it the first time.
Jerkass Woobie: Holden is a pretty bitter character who goes on about the "phoniness" of society but it's clear that his past has left some lasting trauma on him.
Love it or Hate it: It's either a perfect representation of teenage angst or a pointless book about a whiny annoying little git.
Signature Line: The very last lines of the book: "Don't ever tell anybody anything. If you do, you start missing everybody."
Signature Scene: Phoebe riding on the carousel in the last chapter of the book. The scene has the most fan art out of every other scene in the book and nearly every Catcher in the Rye book has the scene as its cover picture (like the one on the Main page).
Tearjerker: Virtually every interaction he has with Phoebe. She's concerned about her brother because he keeps hurting himself and she's genuinely concerned for his well-being. When she receives his note, she drops everything because she's so scared of losing her brother and it's ultimately what drives Holden to get his shit together. Mind you, she's only ten and Holden leaving wouldn't be the first time she's lost a brother.
Wangst: The nonstop swearing and pessimistic, holier-than-thou type of attitude that the narrator had (due to everyone being a "phony") made the book completely unbearable for some.