) "Hashirama's country was a shameful contradiction… Man seeks peace, yet at the same time yearning for war… Those are the two realms belonging solely to man. Thinking of peace whilst spilling blood is something only humans can do. They're two sides of the same coin. To protect something… another must be sacrificed. That is, other than that of, say a dream world."
"I want to obtain all the jutsu and gain a true understanding of everything in this world. The first one to mix blue and yellow called the new color "green". I want to do something similar to that. If blue is the chakra, then yellow is the seal, and green is the jutsu... Just as there is no end to the variety of colors, there are so many thousands...tens of thousands of jutsu in the world as well. But in order to obtain every possible jutsu and truth, it would require an eternity. Only one who understands everything after spending such time on this can be fittingly called the Ultimate Being."
"In order to exist you need a purpose, to exist for no reason is the same as being dead… Then I came to the conclusion that I would love only myself and fight for only myself. If all other people exist to magnify that love, then there is no more a splendid universe than this one…" -Gaara
Itachi's quotes are pretty thought-provoking and correlate to real life well. It's kind of impressive how many real life lessons can be learned from a fictional character, especially when they have limited screen time (considering he's mentioned more than he was on actual panel). I enjoyed everything he had to say (yeah, sounds biased. Ah well. We all know it's true as a fanbase.)
On another note, I also enjoyed...
This quote showcasing Tobi's darkness:
You must be registered for see images
Madara's humor Lol :
You must be registered for see images
Pein's philosophy was quite interesting and believable given the nature of the shinobi world:
You must be registered for see images
I loved Danzo's quote during his death that described his relationship with Hiruzen:
You must be registered for see images
And I liked how Tobirama basically summarized what a Hokage must do here:
You must be registered for see images
There might be a few more I'm missing, though I think that's it for me.
"I want to obtain all the jutsu and gain a true understanding of everything in this world. The first one to mix blue and yellow called the new color "green". I want to do something similar to that. If blue is the chakra, then yellow is the seal, and green is the jutsu... Just as there is no end to the variety of colors, there are so many thousands...tens of thousands of jutsu in the world as well. But in order to obtain every possible jutsu and truth, it would require an eternity. Only one who understands everything after spending such time on this can be fittingly called the Ultimate Being."
"In this society, true power is not attained from mastering all the world's techniques. This is something I have already taught you. When there is something important to protect… that's when a shinobi's true power emerges."
Almost everything edo Itachi said, as well as the things Itachi said to Kisame when they first met.
"You are truly a kind child" - Fugaku
"Because I was called a genius" - Neji
Pretty much all of 698 and whichever chapter it was that they talked after the Danzo fight. But the one in my sig sums all of that up pretty succinctly
Nagato/Pain's little lectures were good too...
There are definitely more, but these were the ones that immediately came to mind...