I am still very unsure about the novels that have made an impression on me through the use of dialogue. I am spoilt for choice and so far I have come up with two candidates.
1) "Crime and punishment" by Fyodor Dostoyevski.
The novel is composed of much inner and outer dialogue as Raskalnikov wrestles with
the poverty of the times in St Petersburg and the repercussions of a double murder. There is much dialogue throughout the novel but the exchange that always made a great impression on me is between Raskalnikov and Sonia in part 4. This is a very long passage where he visits her and the poverty of her surroundings and her reactions are described through inner dialogue. The actual conversation is a long riveting exchange and he comes very close to admitting the murder of Lizaveta her friend who was unlucky enough to be present when he murdered the Pawnbroker.
2)"Animal Farm" by George Orwell.
The interactions between the animals and the levels of dialogue between the aggressive pigs and the other farmyard animals make for some very interesting dialogue exchanges.This with the political theme running throughout make for some really interesting quotes.