i voted for 7 people on the list...
Jenny...didn't expect it. simple as that. i knew that someone, one of what i considered to be the core cast was going to die sometime during S2, but i honestly thought it was either going to be Oz or Cordelia. at that time, they didn't really give much to the show, IMO, so i thought one of them would go. i didn't think it would be Jenny simply because i thought her character had some much more left to give. i wanted to see how she would develop. i was gutted when Angelus killed her, but it was perfectly played and wonderfully written and acted.
Joyce...it was so real. it wasn't monsters, or magic. it was just simple human weakness. it showed us that, even with all there super human abilites, these are still real people, with real lives. no one could fix Joyce and it showed me that Buffy can't do everything. she's just human like the rest of us. Anya's reaction to Joyce's death was heartbreaking and i loved it.
Tara...i remember watching this for the first time, and it didn't register. it was so quick, i was left thinking, what the hell just happened. and then Willow was calling her name, and she was on the floor and it slowly sank in. it broke my heart. i didn't think Tara would die, she was one of the characters i thought would make it to the end somehow.
Spike...i managed to, somehow, remain unspoiled for 'Chosen' so i thought that was it. i thought it was a perfect end for Spike, sacfricing himself to save the world, proving that his soul was really there and going out a hero, a Champion. of course, i wasn't exactly upset that he showed up on 'Angel' but i would have been happy with his death if he'd stayed that way.
Fred...like N4H said, Fred's death doesn't really hit me until that last scene in 'Shell's when she's driving away in the car, looking forward to a new life in L.A. it hurts to think about what happened to her after she left her parents, and part of me wants her to turn the car around and stay in Texas. the 'Please Wesley...' bit tugs at my heart strings a bit, but i always lose it when that music plays in 'Shells'
Wash...now one mentioned him!! Washg's death hit me like a punch to the gut sitting in that cinema, i never saw it coming. i didn't think Joss would ever kill off any of his Serenity crew, but i guess i should have seen it coming...it's Jos after all. Wash saved the crew by landing the ship reletivly safely, and then BAM! he's gone! Zoe's reaction, trying to get him to leave with her, and Mal pulling her away, was hard to watch, but then she bottled it all up to fight the Reavers, not thinking about her own safety, that showed me how much she loved Wash, when she couldn't care if she lived or died, as long as she got the job done.