Midna
"You are a foolish traitor, Midna. Why do you defy your king?"
   — Zant
Notes: There is a distinction here between Zant's values and Midna's. Zant is ambitious, but he also believes (by extension) that the Twili would be better off under his regime and that of Ganondorf. By contrast, Midna understands that things are better the way they were, with light and shadow distinct and unmingling.

"No matter how much you may desire otherwise, you will never be more than a shadow in their world. You cannot consort with their kind!"
   — Zant
Notes: This is some callous foreshadowing on Zant's part, and seems to allude to a growing desire of Midna's to stay with Link and Zelda. Midna has a kind of poignant understanding of this fact, this might be regarded as one of several moments which resolved her to destroy the Mirror of Twilight in the end.

"Midna, I believe I understand now just who and what you are... Despite your mortal injuries, you act in our stead. These dark times are the result of our deeds, yet it is you who have reaped the penalty."
   — Princess Zelda
Notes: Despite Midna's nonchalance with regard to the fate of Hyrule up to thise point, this quote is interesting as it implies that Midna also has a sense of altruism towards the Hylians she at several points previously had held in contempt.

"Only the true leader of the Twili can utterly destroy the Mirror of Twilight."
   — The Sages
Notes: This is both foreshadowing and a plot point, as it sets up Midna's permanent departure from the world of light at the end of the game, shows the falsity of Zant's kingship and sets up a means to travel to and from the Twilight Realm.

"As a ruler who fled her people, I'm hardly qualified to forgive you."
   — Midna
Notes: This is a characterising moment for Midna. Between this line and the in-game justification for her to stay in Link's shadow — that it would distress the Twili to see her as an imp — it seems that Midna is ashamed of her inability to prevent Zant's uprising and protect her people. It makes you wonder what she felt about her banishment: relief?

"Am I so beautiful that you've no words left?"
Notes: Poignant lampshade hanging of the fact that Link never speaks. One of my favourite quotes of the entire game.
   — Midna

Twilight and the Twili
"Tell me, do you ever feel a strange sadness as dusk falls? They say it's the only time when our world intersects with theirs... The only time we can feel the lingering regrets of spirits who have left our world. That is why loneliness always pervades the hour of twilight."
   — Rusl

"You don't have to look so sad! We actually find it to be quite livable! I mean, is perpetual twilight really all that bad?" [...] "What's so great about a world of light anyway?" [...] "Ah, look! How lovely! That black clouds of twilight are so fetching today... I feel so much more at ease here."
   — Midna
Notes: This collection of quotes frames the kind of nonchalance that was typical of Midna towards things of gravitas, particularly the fate of Hyrule, at the start of the game. It also shows the fondness she actually has for the Twilight Realm, an attitude most likely typical of the Twili or at least of their Royal Family, in contrast to Zant's disdain for it.

"When all was chaos, the goddesses descended and gave order and life to the world. They granted power equally to all who dwelt in the light, and then returned to the heavens.
  "The lands where the goddesses descended came to be known as the Sacred Realm. For ages, the people lived at ease, content in mind and body...
  "But soon, word of the Sacred Realm spread through Hyrule, and a great battle ensued... Among those living in the light, interlopers who excelled at magic appeared. Wielding powerful sorcery, they tried to establish dominion over the Sacred Realm.
  "It was then that the goddesses ordered us three light spirits to intervene. We sealed away the great magic those individuals had mastered."
   — Lanayru

"Do you remember what the spirit said about the Fused Shadows? What do you think happened to the magic wielders who tried to rule the Sacred Realm?
  "They were banished. They were chased across the sacred lands of Hyrule and driven into another realm by the goddesses. It was another world entirely... The antithesis of Hyrule, where the sun shines bright.
  "Its denizens became shadows that could not mingle with the light. Eventually, most came to call it the Twilight Realm, and from it, none could return to the world of light... They were forever doomed to live in the twilight, flitting in the half-light of dusk, mere shadows of Hyrule...
  "This is the history of the Twili as it has been passed down from our ancestors..."
   — Midna

"Some call our realm a world of shadows, but that makes it sound unpleasant. The twilight there holds a serene beauty. You have seen it yourself as the sun sets on this world. Bathed in that light, all people were pure and gentle..."
   — Midna
Note: Once again, this time free of the mocking tone that accompanied her earlier extolments of the Twilight Realm, Midna shows her affection for it, particularly prosaically. She also sets up the contrast between the Twili as they were in the Twilight Realm, and pre-banishment.

"The people of our tribe, a tribe that mastered the arts of magic, were locked away in this world like insects in a cage. In the shadows we regressed, so much so that we soon knew neither anger nor hatred... nor even the faintest bloom of desire. And all of it was the fault of a useless, do-nothing royal family that had resigned itself to this miserable half-existence!"
   — Zant
Notes: Contrast this with Midna's attitude towards the Twilight Realm. Zant's views of the world are born directly from his ambition, greed and hate, and are the same ambitions which had the Twili banished to the Twilight Realm in the first place.

"Shadow and light are two sides of the same coin; one cannot exist without the other. I know now the reason the goddesses left the Mirror of Twilight in this world. They left it because it was their design that we should meet. Yes. That is what I believe."
   — Princess Zelda

The Fused Shadows & Mirror of Twilight
"O hero chosen by the goddesses, beware. Those who do not know the danger of wielding power will, before long, be ruled by it. Never forget that. The dark power that you seek is sleeping within Lakebed Temple in Lake Hylia."
   — Lanayru

"Did you honestly mean to take an ancient and withered power like this and turn it against me?"
   — Zant
Notes: Although Zant is eventually defeated by the Fused Shadows, he is technically right that they are less potent than Ganondorf's power — Ganondorf's coming from the Triforce of Power and described in several places as gifts from the goddesses. However, Ganondorf is later defeated himself on account of his arrogance by Link, holder of the Triforce of Courage.

"[T]here's another tale told by my people. Though the goddesses forbade us to return to the world of light, they left one link between the light and the darkness. Something called the Mirror of Twilight was passed to the protectors of Hyrule."
   — Midna

"To think the Mirror of Twilight has the power to change people like that. This world — ALL worlds — can be cruel." [...] "Link, you saw how nasty that monster was, right? The evil within the shards is more powerful than you can imagine. You know we could be assembling something truly terrible here... It could be something that we'll ultimately have to destroy."
   — Midna
Notes: This is both foreshadowing of Midna's final decision to destroy the Mirror of Twilight, and show the train of thought she followed to do it. No doubt it was witnessing the effects of the Mirror fragments that led her to deem it dangerous: something which may not have happened if Zant had not shattered it in the first place.