Gödel, Escher, Bach: An Eternal Golden Braid by Douglas Hofstadter is an intricate and complex study of Strange Loops, Meta Concepts in general and their connection to self-awareness and intelligence. Each chapter is separated from the next by a short fictional piece in the style of Lewis Carroll, which exemplifies the theme of the following chapter.
The Dialogues contain examples of:
All Just a Dream: The Subjunc-TV dialogue is All Just A Hypothetical Situation.
All There in the Index: For example, to find where the book's true end is, search for 'typos'.
Defictionalization: When Hofstadter heard that there was a real Bach goblet, he edited the French version of GEB to make the depiction of the book's goblet the same as the real one.
Breather Episode: The interlude "English French German Suite", consisting of Lewis Carroll's poem "Jabberwocky" in three languages, taking place between two chapters of theories on how the human mind works.
Hidden in Plain Sight: The answers to the puzzles in "Sonata for An Unaccompanied Achilles." Not only is the answer explicitly used in the text, it is also the two puzzles make up the entire word.
Metafiction: Some stories are so extremely meta that they have no content other than discussions of themselves discussing themselves discussing themselves ad infinitum, usually indirectly.
She's a Man in Japan: The Tortoise is referred to as male in the original, but the French word for tortoise is the feminine tortue. Hofstadter, who is interested in the phenomenon of unconscious sexism in language, was delighted when this was pointed out, and gave the French translators the go-ahead to make the Tortoise a female character.
Self-Deprecation: A book about "metal-logic", called Copper, Silver, Gold: an Indestructible Metallic Alloy is mentioned in the dialogues. The Crab says that it's "filled with strange Dialogues about many subjects, including molecular biology, fugues, Zen Buddhism, and heaven knows what else." Achilles responds that "probably some crackpot wrote it". The book is also listed in the bibliography, where it's called "a formidable hodge-podge, turgid and confused". Indeed very little praise is given to its author, Egbert B. Gebstadter.
Self-Fulfilling Prophecy: Commented on if a psychic who could determine the minds of other people was allowed to choose his or her jury if accused.
Subverted Rhyme Every Occasion: In one of the dialogues, the Crab puts on a record of himself singing "A Song Without Time or Season." Here's how it goes:
A turner of phrases quite pleasin', Had a penchant for trick'ry and teasin'. In his songs, the last line Might seem sans design; What I mean is, without why or wherefore.
Textbook Humor: Well, the text wasn't all that serious to begin with, but you have to wonder when Hofstadter describes the DNA of a feline as CATCATCATCATCAT...
To Be Continued: The two Dialogues Prelude... and ... Ant Fugue are, well, two sections of a separated story. The end of the former ends with TTortoise [Sic], while the latter begins with Achilles and CCrab [Sic], using "ATTACCA" as a guide.
The Treachery of Images: Subverted—one character takes the pipe out of the painting and smokes it.