The Flash and Captain Marvel

  For a while, these were two of the most famous superheroes ever to be killed off.  The Flash eventually returned to the land of the living, but despite a few teases, Mar-Vell's death has not been reversed.  I think by this point he is safely resting in peace, I'd be surprised to see a true attempt to bring him back now.  That doesn't mean I wouldn't mind some appearances in flashback sequences, though.