I prefer whichever sounds the best, neither English nor Japanese is my native language anyway. Usually the original voices sound better but I've heard some good dubs as well, like Xenoblade's and Last Story's (British English sounds nice most of the time). I'm probably more used to subs in general - hardly anything gets dubbed where I live, only kids' tv programs really, so I've been reading subs ever since I've learnt to read. --- 3DS: 2406-6325-2795 Currently playing: Dark Souls, Dark Souls II
Sure, english dubs have progressed a lot since 1995, but most of them still feel like not-so-committed, "we're voicing some cartoon" kind of deal. Even if I don't understand 99.5% of the language, it's pretty clear the Japanese take it way more seriously, or at least developped vocal techniques to make it seem like it.
Dub all the way; what's the point of sub if you can't understand Japanese? If you don't speak the language of the voice actors, the voices may as well not be there.
If you DO understand Japanese, then sub is better, but I'd rather be able to understand the voices rather than just filter them out as white noise.
EDIT: Of course, I don't really care if a game comes with only subs, but if a game has dual audio I'll use the dub. --- The arcana is the means by which all is revealed. It matters not who you are... Death awaits you