Well, I certainly enjoy a lot of materials about incest, from the purest romance to the shameless hentai, to me is a huge fetish.
About doing it with brother/father... I don't think I could, specially with my father. Even though it would be a nice scene since I have younger twin brothers., heh.
I particularly don't see any problems about incest, as long as the people involved are comfortable with it. However, now being realistic, about genetic aspects, incest is really bad to the future children, many can be born ill and not even survive, so I guess having kids is the big issue to incestuous couples.