1. "Home sweet home."
Spike is my absolute favorite character in the Buffyverse, and his debut episode was fantastic, climaxing in his effortless killing of the "annoying" one.
2. "Death is your gift."
The finale of season 5 was extremely gripping and masterfully done. It brings you to tears every time.
3. "I died... so many years ago..."
Spike's annoyed look on his face in "Once More With Feeling" as he began to sing was absolutely priceless, and seeing the "big bad" crooning was hysterical, and a good showcase for one of James Marsters other talents.
4. "Shut it, Sit 'n' Spin."
That was the only quote I can recall from Angelus in season 2 right now, so I used that. I LOVED Angel as the big villain of season 2, and everything he did as Angelus made him my favorite villain of the entire series.
5. "I'm bored... Episode One bored."
The addition of Andrew as more or less a regular in Season 7 was one of my favorite things about that season. He added comedy to an otherwise humor-less season.
6. "I didn't give him syphallis!"
The Thanksgiving episode of Season 4 is one of my favorites of all time. So many quotable moments, and everyone's interaction was very entertaining.
7. "Home Sweet... *falls out of car drunk*... home."
Spike's only episode in Season 3, which put a new twist on his debut in Sunnydale. A hilariously funny ep.
8. "Once More, With Feeling"
I already gave a nod to one moment, but now I have to nominate the entire episode. I've seen it at least 20 times and it never gets old.
9. "I can feel it, Buffy. I can feel my soul!"
Spike's sacrifice in the series finale was incredibly touching, and it was extremely suiting to the character that he went out in a blaze of glory, laughing and sneering rather than weeping.
10. *Insert every Xander inspirational speech here.*
Every time Xander opened his mouth in an attempt to rally the troops and give someone support, it was beautifully written. Made his character so much more than "dorky guy who tells jokes".