My favourite superheroes that they killed off were Hawkman and Hawkwoman, Hawkworld flavour.
While I always liked the characters on par with Aquaman in the seventies (peoples that talked with birds and fishes,when I was a kid it fashinated me much more that a man able to fly or superstrong), then Tim Truman infused them with a life that made them fantastic. Surely after his departure from the book they became more predictable, and 0 Hour was worst than a death for Katar, but when it was Grandpa Hawk to be resurrected, I felt betrayed.
Katar's discovery of democracy was a very interesting subtheme of the series, as much the long developing relationship between Katar and Shayera.