Fiorina 161 and Cpl Hicks
So according to Aliens - Colonial Marines, which is canon by the way-despite the reception of the game, Hicks never died in Alien 3, and all those emotional feelings twisted up in a weird way in the opening theme while showing us flashes of the Sulaco on fire, the Alien egg, EEV's being evacuated, etc, are slightly misplaced.
Though with Newt dead--after all Ripley went through to get her at the end of Aliens just weeks earlier in the film setting, is by far the most tragic.