First Japan is a lot more open with their topics and dont care as much about censorship (which i think is retarded) as the US. Second subbed anime is accessible a lot quicker than a dubbed version. Third anime companies in Japan have been going for a looong time so the voice actors are generally more experienced. And finally forth, even if there is poor voice acting all you can pick up as a non-native speaker is raw emotions, making the experience overall more enjoyable (for me).
Well at least these are the reasons why i prefer subbed.
Well at least these are the reasons why i prefer subbed.