I don't know what season we're on, and I don't know what the episode was called, but they were trying to bring back Angelus so they could defeat that magma-demon thing and then they didn't and then everything all worked out happy and "Isn't it great to be a team, everyone!" - and then, the ending. Um. Wow.

Season four - Awakening. I really enjoyed the end of season four too, although...oh crap, I can't say anything else or I'll spoil you. Oh well. ;)
I love the ending though, when Angel says Buffy's name. As if Cordelia could give him a moments pure happiness, yeah right! See, it really was never about the sex.

Okay, I'm done now. :)