I found this thread just recently from the "Lost and Found" thread, and thought it was really cool. Of course, it turns out it isn't as old as I'd thought, it just got pushed back to the 3rd page, but I'm gonna post anyway to bring it back up front.
Riku- (on destiny islands as the darkness starts to swallow him) "I'm not afraid of the Darkness!"
Ansem- "You have come this far and yet you have learned NOTHING!"
Sora- "I dunno" (his response to a rather philosphical question posed by either Kairi or Riku, a very effective break from the somber tone of the conversation)
Also, I can't remember his last bit of dialogue with Riku, when he and Riku are first fighting over Kairi's heart. If somebody could please fill me in, I'd appreciate it.
Riku- (in CoM I know, but still an awesome quote/conversation).
Riku- What are you making me choose now?
Red- Which road will you take? The path to Light?... or the path to Darkness.
Riku- Neither. I'm taking the middle road.
Red- You mean the twilit road to nightfall?
Riku- No. The road to Dawn.
Also, as a parting quote, I often like to mix in quotes that tie in with KH but aren't necessarily from the game itself. Kudos to anyone who knows the source of this one-
"Darkness is the greatest teacher.
A tribe of the Quiet Land once had a rite of passage in which the aspirant was buried alive, deep beneath the earth, where no light could find him and no ear could hear his sobs and his screams. This was the final rite; after a span of days spent in such a coffin the aspirant was released, and numbered among the wise.
They did this because they knew:
Darkness is a knife that peels away the rind of what you think you know about yourself. The shades of your pretenses, the tones of your illusions, the layers of deception that glaze your life into colors that tint your world-- all mean nothing in the darkness. No one can see them, not even you.
Darkness hides everything except who you really are."