I'll have to agree with the first poster. Spike's "Rest in Peace" was completely within character of Spike and I loved the classic dead pose on top of the coffin he did. Him getting in Buffy's face was just great.
Then "Walk Through the Fire" for not only the harmonies but also because it signifies that even though all these relationships are falling apart, the group knows they have to band together and stop the musical madness.
Finally, I thought "I'll Never Tell" was great just for the hilarity. Plus seeing Anya in her skivvies... :whistle:
Edit:
I also found this line is one of the songs near the end that is just funny.
Anya: She came from the grave much graver.
Spike: First he'll kill her, then I'll save her.
Tara: Everything is turning out so dark.
Spike: No, I'll save her, then I'll kill her.
Willow: I think this line's mostly filler.
Giles: What's it gonna take to strike a spark?
I love how Spike gets his plans mixed up and Willow singing her one line of her line is just a filler. LOL Gets me laughing everytime. :lmao: