I have recently been wondering about what constitutes a productive death of a character in a work of fiction like Lost. It has been on my mind since Ilana blew up in the same fashion as Arzt during "Everybody Loves Hugo".
I realized that Arzt's death got full value of what his character was worth, a throwaway at the end of S1 to add tension to all scenes involving dynamite. But Ilana was just the opposite, so many unanswered questions about what she knew about Jacob, the Island, for a tension we already knew was there.
So I wondered what your opinions were, on character deaths in Lost you deemed productive (no matter how difficult it was to let go), vs. the cop-out (there was more there) deaths that have occurred in the six seasons so far.
I would vote that Boone, Charlie, and Faraday were all productive deaths to the story. But interesting characters such as Libby, Abaddon, and Ilana died before their full potential was realized.