What anime have you enjoyed because of the quality of the character dialog? By that I mean what anime do you think had more clever, witty, subtle, multi-layered or meaningful dialog than most?
I've never made a list for this, but I recall thinking how much I enjoyed:
Death Note
Earl and Fairy
...because of the character dialog.
I'm sure there have others. But I have a bad memory recalling for this sort of thing.
"Innocence" (a.k.a Ghost in the Shell 2) really sticks in my mind for having clever banter with double meanings. Every other line was a wise quote or saying taken from various sources; it was pretty fun ^^.
I have to say Serial Experiments Lain had amazing dialogue, as far as the monologue and the constant questionings, I loved it, was very philosophical.
Another that some may not agree with me for is Chobits. There was something about Chii maturing and then her inner thoughts as Elda/Freya that made for really great dialogue.
For me I would say the Crest/Banner of the Stars series was quite good including the actual Ahb language created by the novelest Hiroyuki Morioka.
Shakugan no Shana & Kurau Phantom Memory also stand out.
"Like the wind crying endlessly through the universe, Time carries away the names and the deeds of conquerors and commoners alike. And all that we are, all that remains, is in the memories of those who cared we came this way for a brief moment." Harlan Ellison
Your purpose is me I would say the CrestBanner of the Stars series was quite good including the actual Ahb language created by the novelest Hiroyuki Morioka.
The Three Laws of Robotics:
1. A robot may not injure a human being, or, through inaction, allow a human being to come to harm.
2. A robot must obey the orders given it by human beings except where such orders would conflict with the First Law.
3. A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.
-I, Robot (Asimov)
Great topic Keropi - kinda upset I didn't come up with it.
Including many of those already mentioned, I also found Ergo Proxy to have some of the most complex dialogues and monologues ever written for anime. It is a deft mix of both philosophy (with many of the characters being named after famous philosophers) and psychology that takes several viewings in order to absorb all the little nuances that are scattered throughout the series.
Another one that comes immediately to mind (which also happens to be cyberpunk) is classic Æon Flux. This anime so full of double entendres and innuendo that I'm still catching stuff to this day - only going to prove how slow I can be on the up-tick.