Following conversations with my fantastic Star Wars students this semester, I've been going back through some of the literature to find some favorite Qui-Gon Jinn-related quotes (above and beyond these that I posted earlier).
From Jude Watson's Deceptions (2001):
Yoda awaited them in a meditation room, the place he favored now for conferences. Obi-Wan knew that Yoda had often met Qui-Gon at his favorite bench in the Room of a Thousand Fountains. Yoda never sat there now. It was the only visible sign that Yoda was still in deep mourning for his friend.
Qui-Gon had been torn from him too soon, and Obi-Wan still felt his presence at his shoulder. He even knew what Qui-Gon would say right now.
You cannot make friends for your Padawan, Obi-Wan. You can only show him through your own actions how important connections are to you.
Qui-Gon had done that. Obi-Wan was still running into beings throughout the galaxy who came up to him and spoke reverently or glowingly or humorously of their deep friendship with his Master. Obi-Wan hadn't realized how many connections Qui-Gon had forged with the most unlikely sorts.
"Qui-Gon must miss you."
Obi-Wan's bright gaze dimmed. "Andra, Qui-Gon is dead. Three years now."
Her smile vanished, and sorrow filled her eyes. "I did not know. I am sorry. The galaxy is diminished without him."
"Yes," Obi-Wan said. "That is exactly how I feel."
From James Luceno's Cloak of Deception (2002):
Many held the opinion that Qui-Gon would have been seated on the council, if not for his penchant for bending the rules and following his own instincts -- even when those instincts conflicted with the combined wisdom of the council members. This had not endeared him to his loftier peers.
"...I always worried that I lacked the temperament to become a Padawan, let alone a Jedi Knight," Obi-Wan added. "I fought harder than anyone to mask my self-doubt."
Qui-Gon glanced at him askance. "If you had fought a bit harder, Padawan, you surely would have remained in the Agricultural Corps. It was when you stopped trying so hard that you found your path."
"I couldn't keep my mind in the moment."
"And you still can't."
"...Perhaps our meeting on Bandomeer was a fork in the path I shouldn't have taken."
Qui-Gon finally turned to him. "There are many paths to take, Obi-Wan. Not all of us are fortunate enough to find the one with heart, the path the Force has set before us. What do you find when you search your feelings about the choices you have made?"
"I feel that I've found the right path, Master."
"I agree." Qui-Gon clapped Obi-Wan on the shoulders, then smiled as he turned to regard the students. "Even so, I think you would have made a good field hand."
Everyone fell silent except for Yoda.
"A true Knight, Qui-Gon is," he said, with a note of gentle rebuke. "Forever on his own quest."
"Palpatine represents Naboo," C'baoth added.
"Just the world for Qui-Gon," another human Jedi said from farther along the walkway.
C'baoth nodded. "More indigenous species in one square kilometer than you normally encounter on a hundred worlds." He smiled faintly. "I could easily see Master Qui-Gon losing himself there."
"Defying a direct order from the High Council, you'll be."
Qui-Gon didn't argue the point. "My duty is to the Force, Master."
Yaddle studied him for a long moment. "To what end, Qui-Gon? To what end?"
"I did what I had to do, Masters," Qui-Gon said, without apology.
Yoda loosed a prolonged sigh. "Blame you, we don't, Qui-Gon. But exasperate us, you do."
Qui-Gon inclined his head in a bow.
From James Luceno's Darth Plagueis (2012):
He [Dooku] ran a hand over his short beard. "As skilled as I am with a lightsaber, I've turned out to be an ineffectual teacher. Master Qui-Gon Jinn has become a solitary and secretive rogue."
"Qui-Gon believes that the boy -- Anakin is his name -- stands at the center of a vergence in the Force, and believes further that his finding him was the will of the Force."
...The fact that Qui-Gon had identified Maul as a Sith was to be expected; but Dooku's news about a human boy at the center of a vergence in the Force had come as a shock. More, Qui-Gon saw the boy as the Jedi's prophesied Chosen One!
The boy would change the course of history.
Maul had to kill Qui-Gon, to keep the boy from being trained.
Qui-Gon was the key to everything.
"It pained me to learn that Master Qui-Gon had been killed." He [Palpatine] paused momentarily. "Was it his death that firmed your decision to leave the Order?"
"To a degree," Dooku said, scowling.
"Eventually I will find him -- or her -- and with any fortune before the Jedi do."
"To avenge the death of Master Qui-Gon," Palpatine said, nodding, and aware that Dooku was staring at him intently.
"The thought preoccupied me for some time, but no longer."
Palpatine turned his head slightly. "Then why seek this one?"
"Because I suspect that Naboo was only the beginning -- a kind of opening salvo. The Sith want to see the Republic brought down. Much as you and I do."