eh, except for Meg. On Family Guy, Meg was the only one who seemed to have real problems and issues to deal with. I think that made her both the least noticable character and at the same time the easiest to relate to.
As for Seinfeld, let me just chime in to say that I just consider the change an evolution (and agree that the last episode was brilliant because it recognized that), and that I have the same middle name as George.