Here's my list of characters who should be killed off any time the situation allows for it.
Jimmy Olsen
James Olsen
James Bartholomew Olsen
J. B. Olsen
Jimmy 'the annoying' Olsen
Jim Olsen
Justin Whalen
Any other character would actually need to further a plot point, or be used to expand the characterization of another character.
Tank (who just remembered that he did imply Lois' death in a fic, but it was a noble death where she sacrificed herself to save Superman from being made a pawn of the bad guys)
