Harry Potter and the Half-Blood Prince

chapter 1 [the Other Minister] p.18
“But for heaven's sake, you're wizards! You can do magic! Surely you can sort out, well, anything!”
Scrimgeour turned slowly on the spot and exchanged an incredulous look with Fudge, who really manage a smile this time as he said kindly, “The trouble is, the other side can do magic too, Prime Minister.”

chapter 3 [Will and Won't] p.45-46
“However, let us assume that you have invited me warmly into your house. It is unwise to linger overlong on doorsteps in these troubled times.”

(...)any man who could look at Harry and say “excellent” was a man with whom he could never see eye to eye.
“I don't mean to be rude,” he began, in a tone that threatened rudeness in every syllable.
“... yet, sadly, accidental rudeness occurs alarmingly often,”

chapter 4 [Horace Slughorn] p.62 & 77
“For future reference, Harry, it is raspberry... although of course, if I were a Death Eater, I would be sure to research my own jam preferences before impersonating my self.”

“I take my hat off to you, or I would, if I were not afraid of showering you in spiders.”

chapter 5 [an Excess of Phlegm] p.87 & 103
“As if St. Mungo's didn't have enough to do already!”
(o please!! xDDD!!)

“Yep, ten ‘Outstandings’ and one ‘Exceeds Expectations’ at Defense Against the Dark Arts.” He looked down at her, half-amused, half-exasperated. “You're actually disappointed, aren't you?”

chapter 7 [the Slug Club] p.138-139
“Hi, Harry, I'm Romilda Vane,” she said loudly and confidently. “Why don't you join us in our compartment? You don't have to sit with them,” she added in a strange whisper, indicating Neville's bottom, wich was sticking out from under the seat again as he groped around for Trevor, and Luna, who was now wearing her free Spectrespecs, wich gave her the look of a demented, multicolor owl.
“They're friends of mine,” said Harry coldly.
“Oh,” said the girl, looking very surprised. “Oh. Okay.”
And she withdrew, sliding the door closed behind her.
“People expect you to have cooler friends than us,” said Luna, once again displaying her knack for embarrassing honesty.
“You are cool,” said Harry shortly.

chapter 9 [the Half-Blood Prince] p.180
“Do you remember me telling you we are practicing nonverbal spells, Potter?”
“Yes,” said Harry stiffly
“Yes, sir.”
“There's no need to call me ‘sir’, Professor.”

chapter 12 [Silver and Opals] p.239 & 241
On the other Hand, the Prince had proved a much more effective teacher than Snape so far.

“If he'd been a budding Death Eater he wouldn't have been boasting about being ‘half-blood’, would he?”

chapter 16 [A Very Frosty Christmas] p.348
“Dumbledore's man through and through, aren't you, Potter?”
“Yeah, I am,” said Harry. “Glad we straightened that out.”

chapter 17 [A Sluggish Memory] p.356, 357 & 370
“I am a wizard, not a baboon brandishing a stick”.

“He accused me of being ‘Dumbledore's man through and through.’”
“How very rude of him.”
“I told him I was.”

Voldemort said:
“Sir, I wanted to ask you something.”
“Ask away, then m'boy, ask away...”
“Sir, I wondered what you know about... about Horcruxes?”

chapter 18 [Birthday Surprises] p.379
and then, Harry said...
“Sir, I wanted to ask you something.”
“Ask away, then, my dear boy, ask away...”
“Sir, I wondered what you know about... about Horcruxes?”
(nothing more to be said ^^)

Chapter 19 [Elf Tails] p.404
“Well, all I say is that is was a lucky day for the Weasleys when Ron decided to sit in your compartment on the Hogwart Express, Harry.”

Chapter 20 [Lord Voldemort's Request] p.443,446
“Greatness inspires envy, envy engenders spite, spite spawns lies.”
(And lies will guide you to the dark side, so it's said.)

“You see, we have never been able to keep a Defense against the Dark Arts teacher for longer than a year since I refused the post to Lord Voldemort.”

Chapter 21 [The Unknowable Room] p.449
“I love you, Hermione,” said Ron
(And there's nothing more to be said ^^)

Chapter 22 [After the Burrial] p.484
“Farewell, Aragog, king of the arachnids, whose long and faithful friendship those who knew you won't forget! Though your body will decay, your spit lingers in the quie, web-pun places of you forest home. May your many-eyed descendants ever flourish and your human friends find solace for the loss they have sustained.”

Chapter 24 [Sectumsempra] p.514
She could not possibly know that his insides were suddenly dancing the conga.

Chapter 27 [The Lighteniong-Struck Tower] p.590
“Only your Phoenix lot got in the way...”
“Yes, they do that,”

Chapter 28 [Flight Of The Prince] p.604
“You dare to use my own spells against me, Potter? It was I who invented them −I, the Half-Blood Prince!”

Chapter 29 [The Phoenix Lament] p.623
“I am good-looking enough for both of us”
(go Fleur!!)