I think it depends on what company does it. I have thought that Bandai has done a fairly good job of dubbing shows(from what I have seen). Other companies are still young and upcoming and they continue to get better.

I can watch either as long as I think the voice acting is good. Ghost in the Shell, .hack, Cowboy Bebop and some others all have good voice actors that fit the characters.

I also usually watch subtitled stuff because it comes out on the internet first and free