I won´t repeat your choices so I´ll try to use my memory:
- Nicole Chapman (Nia Peeples) on "Fame": She wanted out for the usual reasons but didn´t know what was ahead for her character. The most charismatic character of the series since Valerie Landsburg´s Doris left, Nicole was killed off in a mid-season episode of the last year, and off-screen. Suddenly, they said she had been killed in a car accident because the driver, one of his friends (and, conveniently, a non-recurring character), was drunk after a party they attended.
The result was a bleak, depressing episode where they treated the subject of "don´t drive drunk" (minus the Stevie Wonder song), since this was the intention of the then completely oblivious network bosses. The remaining episodes of that final season introduced new characters who, of course, couldn´t make the fans forget Nicole and Nia, who probably was the only young star left who could dance, sing and act, all wonderfully. She went on to star in "Walker Texas Ranger", "Pretty Little Liars" and a few B-movies, and even today, she´s a gorgeous, multi-talented woman.

There also was a sense of unavoidable fate in those latter episodes (like happened with both "Dallas" and "Falcon Crest") that lead to the also unavoidable cancelation of the TV series. What was worse is that Nicole was never mentioned again after her death´s episode, and everybody and their mother returned for the final episode ever, except those who were sort of "over" the show: Janet Jackson and Lori Singer. Not even in that episode Nicole was remembered by her ex-boyfriend Jesse...

- If we have to consider miscarriages as deaths, then I´d say that Maddie´s miscarriage on "Moonlighting" was a total shock to me. After 3 seasons of "Will they / won´t they", and one season of Maddie considering if she should marry Dave or her new beau, the Season 5 Premiere featured one of the cruelest plots ever: Bruce Willis was shown as Maddie´s fetus inside the womb (really! see pic above!) and, after a very imaginative, funny hour with clips and all, suddenly, Maddie begins to feel pain and faints, and then she is told she has lost Dave´s baby. That was the last straw for the series, which never recovered from that. Season 5 was its last, of course, and there was no spark between the leads anymore.
- Of course, of all the "Knots Landing" deaths, Laura´s was the most devastating to me, but at least this was handled well plot-wise (if not for the actress...). Some of the most heartbreaking scenes of the show come from the episodes dealing with this, and McCashin did her best acting there, which was no surprise for the audiences since she was a strong actress all the way.
- I also was rather shocked by Nate´s death on "6 Feet Under", because he supposedly was cancer-free in previous seasons. But that was no surprise in such a magnificent show like that one, and death was undoubtedly its main subject. Lili Taylor´s character´s death also was a big surprise, though, let´s be honest, who liked her when she died...? (oh Lisa, how we hated ye...)

- Also very sad was the "non-death" of Sara, Michael´s girlfriend, whose head was literally found in a box, on "Prison Break". After that, one just could only guess that she wouldn´t appear again, but actually it was not Sara´s head in that box...in a "deus ex machina" move that sort of "touched" the show´s credibility the way it happened with "Dallas" after Bobby´s "resurrection". Michael´s death also was very sad but, you know, he wasn´t dead either!! That´s what the upcoming sequel will try to make us believe. Though, who doesn´t want a series with two gorgeous hunks like Wentworth Miller and Dominic Purcell? Who needs a decent plot here...?
- A few more shocking deaths:
- Brody (Damien Lewis) on "Homeland" (not really unexpected but...);
- Patriarch Bill (Pullman) on "Big Love" (this one really was unexpected but well-handled);
- Anne Boleyn (Natalie Dormer) on "The Tudors" (kudos to the actress for this, because it probably was the least surprising death in TV history, as were those of the other wives of King Henry VIII);
- Ma Petite (Jyoti Amge) on "AHS: Freak Show" (you had to be heartless to not be sorry for her);
- Charlie (Dominic Monaghan) on "Lost" (right time for killing off a good character, which is unusual!);
- Gary (Peter Horton) on "30something": After spending the whole series suffering for Nancy´s (Pat Wettig) future due to her cancer, once she was healed, the writers killed off gratuitously one of the most endearing characters of the show in its last season. Low blow people. You did deserve the cancelation after all.