Hamlet and Holden Caulfield

Hamlet is the Holden Caulfield of Shakespearean times. All the is-ing and the seeming, the questioning of life's purpose, the dull outlook on the world--these are such Catcher and the Rye-esque themes. Of course, Shakespeare came before Salinger, but I became acquainted with Holden before I even thought about Hamlet, and so I find myself comparing the brooding, age-unknown royal from Denmark to the brooding, teenage WASP from New England.
As Mrs. Clinch actually pointed out, Holden's hatred for "phonies" is similar to Hamlet's conflict with the "seeming" and the "is-ing" that's going on around him. Aren't "phonies" seeming? The whole premise of the "phony" thing Holden's got going on is that the world is filled with fake people who act certain ways for varying ends. From his roommate to his parents, to practically ever adult he meets, Holden considers himself to be surrounded by infuriatingly inferior people. Grown-ups are the epitome of "seeming" in Holden's dreary world, as exemplified when old Spencer tells him "Life is a game that one plays according to the rules." As such, the adults of Hamlet's world are also riddled with lies and secrets and oh-so-much pretending. Polonius is the very embodiment of slippery tendencies. He lies, spies, manipulates, and uses in order to achieve his ends--which are either to keep up his image or to improve it by ways of his son and the king respectively. While Holden witnesses the falsehood of his New England World, Hamlet witnesses the falsehood of his Denmark World and the two suffer very deeply as a result.
Hamlet's famous "To be or not to be" line is the question for both characters, the main theme for both works. Not only does it capture the question of "seeming" versus "is-ing," of "real" versus "phony," but it also captures the two character's inner battle with the will to live and the un-will to live. Hamlet outright states that he might kill himself if "God had not set his cannon against self-slaughter," and Holden provides countless instances that support a diagnosis of depression. Hamlet views the world as "weary, stale, flat and unprofitable," and Holden views life after childhood as pretty much equivalent to a life led by the devil. Hamlet views people as nothing but dust--man does not please him. Holden views people as a bunch of morons and perverts. And although the two characters say these things with such dignity and near haughtiness, there's a distinctive sadness to their words. Who wants to live in a world filled with liars, spies, phonies, and morons? Neither of them truly do. That's why Hamlet broods so often and speaks of "being" and "not being" and of the freedom that comes from sleeping and dying. That's why Holden likes museums--because, just like the state of death, nothing ever changes. The two of them suffer so deeply from their seemingly superior outlooks on the world. They are alone, depressed, and desperate. All either of them really wants is to run away from it all.
The main difference between the two is that Holden spends the whole book running and avoiding his fate, while Hamlet "seems" as much as any other character, "plays the part" as much as Polonius or Claudius, and only ever questions fate, but does not act against it.