JR Ewing in New Dallas will forever be the ultimate devestating one for me. Not only had the character died but so had the actor. I had grown up with ol' JR. It was a real end of an era.
Emmerdale has had a few actors die on the job. All very sad but the most for me were Seth and Turner as characters. Seth's death I found also troubling as I had met and chatted with Stan Richards just a month before he died.
EastEnders - if I had been watching at the time, both Den Watt's exits I would of found saddish.
Also in EE Pat. I stopped watching again not long after that. I only started dippining in and out again when Kathy returned.
Re EE, I found Glenda's exit sad. For once in her life she had done the right thing, yet she got punished for something Phil and Shirley had done. I felt that there was still milage in Glenda at the time she was axed. With Ronnie leaving over the baby swap, Roxy could of done with her mother around as well. I am only sad about Ronnie and Roxy's departure because it means no more Glenda. Although they sort of did give Glenda a long overdue ending in May - albeit an unsatisfactory one. As to Ronnie, her time has come and I don't really think she should of come back after her last exit. As to Roxy, I think they could of done more with her but the writers never let her develop away from Ronnie for too long.
Coronation Street - Deirdre Barlow was a biggy. Mike Baldwin, Linda Baldwin and Kylie Platt. Although in Kylie's case I can see that for creative purposes killing her off was probably for the best. She didn't leave any unfinished business and her story was told. I will miss her though.
Falcon Crest - Pamela Lynch.
Prisoner: Cell Block H - quite a few.
I generally only feel saddened by characters departures if the actor dies (that is devestating); they are longterm legendary characters or they leave lose ends.