

What is the death that hit you harder in all of Starcraft? I have weird tastes, mine is Aldaris, since everyone just believes he's being an ass. 2nd one is the Overmind (it was fatherly and only wanted the best for its "people")
but since the Overmind is revived many times it doesn't have as much impact. Aldaris never even gets mentioned again which is more tragic, even though he was only rejecting allying with (evil) Kerrigan.
Of course Fenix 2nd death was also very sad (you also have to kill him) and would be #1 if not for what happens in SC2: "Somehow, Fenix returned... again"