I used to think I couldn't watch the show without him, but now I feel like I could. As much as I love Jack I am satisfied with what I have seen of him and if someone were to take his place I wouldn't be left feeling like I wanted more Jack. He makes the show what it is, but I think that the show has had a great run and I wouldn't mind seeing some major changes. I would prefer to watch Kim take his role as the lead, but if I couldn't have her then Renee would be fine too. I don't think we could have another male lead as we would always be comparing him to Jack. A female lead would be different enough to make it a refreshing change.