it's so hard to choose just one...so here's my list...
1) Cordelia...Angel's face was so emotional, it was like DB was really feeling it, that CC wasn't coming back. And they had FINALLY kissed in this ep!! i was devestated!
2)Tara...she was in the credits!! FINALLY! and then when you see willow's shirt, all red...i didn't even notice the bullet wound in Tara's chest at first...and then she fell and so did my tears.
3)Fred...it took so long...it was so painful to watch, and her last line was like a knife in my heart. the flash back in the next ep was almost as bad.
4)Doyle...he was my fave character!! he finally accept the demon in him...just in time to save the lives of dozens of other half-breeds. And Croft Storm is so right...it's even more painful to watch now.
5)Wesley...THE saddest line in the show was when Illyria says to Wes 'Would you like me to lie to you now?' i knew then that Wes wasn't gonna make it to the alley.
and every other death deserves a mention, because every single one of them was emotional in its own right...these are just the worst ones for me...