I'm sorry, but this topic needed to be made despite my recent one of movie quotes. I mean this show got on its feet due to the dialogue.

"Look at me, I'm a blood-sucking fiend!"
- Willow, "Dopplegangland"

"To make you a vampire they have to suck your blood. And then you have to suck their blood. It's like a whole big sucking thing. Mostly they're just gonna kill you."
- Buffy, "Welcome to the Hellmouth"

"It's a big rock. Can't wait to tell my friends. They don't have a rock this big."
- Spike, "Becoming, Pt. I"

Uhh I have more but I'll stop for now.

OMGOMGOMG
LOLZ
"its a doodle, i do doodle, you do doodle too."
-willow, gingerbread.

Ahh
yes
uhm..
lets see

"I might be dead, but im still pretty."
--buffy, prophecy girl

"that might be the best thing i ever had in my mouth"
--buffy

"Why would anyone want to kiss rocks?"
willow

"xander: do yout think she'll get teh sign?
buffy: I dont think she can see the sign, why is it so pale?
xander: Yellow crayon, you know, on the bluff..."

Two words:

RANDY GILES?!?!

HAHHA i love that quote
HAHAHHA

<3

"why not jsut call me honry giles, or desperate for a shag giles, I knew there was a reason I hated you!"

"oo pretty, will it hurt teh carpet?"

^ HAHA. Another great one from "Tabula Rasa":
Spike: I must be a noble vampire. A good guy. On a mission of redemption. I help the hopeless. I'm a vampire with a soul.
Buffy: A vampire with a soul? Oh my God how lame is that?

Ahh and one of my favorite quotes of all time:
"Passion. It lies in all of us. Sleeping.. waiting.. and though unwanted.. unbidden it will stir, open its jaws and howl. It speaks to us... guides us... Passion rules us all. And we obey. What other choice do we have? [Skip to end of episode] It sometimes hurts more than we can bear. Emptied rooms, shuttered and dank.. Without passion, we'd truly be dead."
- Angelus, "Passion"

Aww... the only quote I remember was when buffy's all "I'm Buffy, and you're history".

Spike: Oh, listen to Mary Poppins. He's got his crust all stiff and upper with that nancy-boy accent. (everyone looking at him) You Englishmen are always so... (pauses) Bloody hell! (ticks off on his fingers) Sodding, blimey, shagging, knickers, bollocks, oh God! I'm English!
Giles: Welcome to the nancy tribe.
- Tabula Rasa

This is the only one I remember:

Willow: Isn't she acting like, a you know... B-I-T-C-H?
Giles: don't you think we're old enough to not spell out words like that?
Xander: Bitkuh?

Wow...I actually know some of these.

One of my very favs -

"What did you just see your life pass before your eyes? Cup of tea, cup of tea, almost got shagged, cup of tea, cup of tea."
(Spike to Giles)

- Bargaining, Part 1

^ Hahaha. I think Spike wins for the best quotes, or at least the most quoted.

Buffy: What are you doing here? Five words or less.
Spike: (Counting on his fingers)Out for a walk...BITCH!