[xyzone]

Short answer is both. Just talking about professional stuff, not fansubs, I generally won't buy something if it doesn't have dual audio, which is rare (in stuff officially released on this side). Not because I need both but because all the releases today have it, so not having it is lazy. I see nothing wrong with dubs if done well, which today is most all major releases. But to be missing the original track seems lacking. I know I can't fluently understand spoken Japanese in real time, so I don't have to pretend like I do, who cares. But if I absolutely had to choose only for for some strange reason, I would go with English if it was a quality dub; although back when you only had one choice in the medium (tapes), [most] dubs were crap and I would not prefer, no debate needed. So it's moot.

Obviously only for animated content. For live action stuff, I really, really hate dubs in any language.