Specifically, the “Orb of Thesala.” A “spirit vault for rituals of the undead.” Also useful as a new age paperweight.
I missed the episode, so I’m relying on the info in this thread for info about it. I wonder, if Angel said “Buffy!” at the happy moment, might that have ruined it a bit and prevented it from being perfect happiness? Nothing ruins that moment like saying the wrong name…
The moment was when he was having his soul removed, after he and Cordy, um, finished.
Or destroy the world…
… which causes the mass migration into space, THUS setting up the story for Firefly!
Ethilrist:
Joss Whedon doesn’t have such a bleak outlook. In the Joss-written comic book Fray, about a 25th-century Slayer, we’ve learned that an “early 21st-century Slayer” did something so huge and momentous that vampires, demons and other such Big Bads disappeared from the Earth entirely for hundreds of years.
And there stopped being Slayers too. Melaka Fray is the first new Slayer since that unnamed 21st-century one (Buffy? Faith? Who knows?).
So I think it’s likely that’s more the direction Joss is headed with his mythology.
[Horseshack voice] Oooh! Oooh! Oooh![/Horseshack voice] I have one: Faith in “Enemies” (Season 3).
In case you don’t remember, it’s the episode where Faith tries to seduce Angel so he will lose his soul and ally with the Mayor. She fails because Angel is a one-woman kinda guy. So the Mayor contracts with some sort of wizard to forcibly extract Angel’s soul. Faith comes into Angel’s house, pours some blood on him and the wizard supposedly extracts his soul. “Angelus” appears and after a brief fight, Angel and Faith do the nasty.
Later we find out that the wizard was indebted to Giles and Buffy and Angel concocted a scheme to have the wizard PRETEND to steal Angel’s soul. Faith is so fooled that she and the Mayor reveal all the secrets of the pending Apocalypse. Then the bombshell:
Buffy: How could I have not known you were capable of such evil?
Faith: I don’t know, B. I guess I’m the world’s best actor.
Angel (from behind): Second best.
Afterward Buffy falls into a pit of depression because even though she asked him to pretend to be Angelus, she didn’t realize he’d take it so far. Besides the matter of dealing with her boyfriend sleeping with a former friend, she also has to deal with the fact that she can never have him again the way Faith could.
And so, it is revealed that all sex does not = Angelus. Just soul sex. If you know what I mean.
We never saw them shagging so saying Faith and Angel shagged is extra-textual conjecture.
Otto, I just watched the episode and IMO it’s pretty clear from the text that they did.
The first scene is Angel and Buffy walking out of an erotic movie. They are both uncomfortable that they are hot and bothered and then have to be chaste. This sets up the theme of the episode: sex turning into your enemy.
And, FTR, we DO see Angel and Faith writhing around on the floor. That’s as much as they showed when Xander and Faith got in on… and I think we all figured out that they did the deed.
After Angel revealed himself to be pretending to be Angelus, Buffy is clearly still upset about something. She visits him at his home and he looks very contrite. (What in the world would he be so apologetic about if it wasn’t about shagging Faith? That he saved the world? That he punched Xander? That he kissed Faith? I don’t think so.) He said, “I know I was only doing what you asked me to do, but I’m sorry.”
Buffy then said something like, "I guess I just didn’t know it would go “that far.”
Yup, they shagged. 
Did he ever “pay his debt” to the three “mmmm Angel!” witches? Cordy sure didn’t want to…
I still dispute that Faith and Angel had sex. Buffy and Angel’s exchange on the subject from “Earshot”:
Not to mention that neither Faith nor Buffy nor Angel state it at any point during any subsequent encounter, and there’s no way Faith wouldn’t have used it to throw Buffy or Angel off stride during a fight. So no, they didn’t shag.