"I got a bang out of it" is reserved for special situations and has a fairly clear meaning--a sense of amusement or "kicks". At one point we read that Holden gets a "big bang." In the first few chapters of the book Holden describes how Mr. Spencer got a "big bang" out of buying an "old beat-up Navajo blanket." I found 8 instances of the word "bang" used in this way or a variation.
"It really does" and associated variations are often repeated. It seems to be some cross between a nervous tic and a joke. Early in the novel I wondered if this phrase is a red flag when Holden is being an unreliable narrator, but as I kept reading no obvious pattern of inaccuracy emerged. I found 49 instances of "really am/is/isn't/was/do/don't/does/doesn't" when used as a standalone sentence, phrase, or interjection. (I may have missed some linking verb combinations.)
"It killed me" is the least clear of Holden's sayings. Does it express frustration or amusement? Both? Either, depending on context? Holden uses it frequently during his late-night conversation with Phoebe, and he evidently has the highest regard for her. On the other hand, we have this quote from Holden's conversation with Lillian Simmons and Commander Blop:
Then she left. The Navy guy and I told each other we were glad to've met each other. Which always kills me. I'm always saying "Glad to've met you" to somebody I'm not at all glad I met. If you want to stay alive, you have to say that stuff, though.The subtext of the novel is crucial to interpreting this phrase. I found a total of 34 instances of "killed/kills/kill" used in Holden's characteristic way.
The words "phony/phoni-" appear 49 times in the text. Similarly, "crumby" appears 21 times and "lousy" appears 50 times. [Update: A quick search reveals that "goddam" appears in the novel 245 times.]
"Nobody." as a stand-alone sentence appears twice in the novel to great effect. (A third is used by Holden in his drunk phone call to Sally but it does not fit the same pattern.)
"[...] Am I late?" I told her no, but she was around ten minutes late, as a matter of fact. I didn't give a damn, though. All that crap they have in cartoons in the Saturday Evening Post and all, showing guys on street corners looking sore as hell because their dates are late--that's bunk. If a girl looks swell when she meets you, who gives a damn if she's late? Nobody.
I thought probably I'd get pneumonia and die. I started picturing millions of jerks coming to my funeral and all. [...] Then I thought about the whole bunch of them sticking me in a goddam cemetery and all, with my name on this tombstone and all. Surrounded by dead guys. Boy, when you're dead, they really fix you up. I hope to hell when I do die somebody has sense enough to just dump me in the river or something. Anything except sticking me in a goddam cemetery. People coming and putting a bunch of flowers on your stomach on Sunday, and all that crap. Who wants flowers when you're dead? Nobody.I found a 1959 article in the journal American Speech which indicates that contemporary reviewers of the novel found that Holden's language "struck the ear of the contemporary reader as an accurate rendering of the informal speech of an intelligent, educated, Northeastern American adolescent." (You can read it here from a UIUC network or here to log in from home.)
To conduct my word and phrase counts, I copied the full text of the novel from a pdf e-book into a text document, though which I could search using Notepad++.