I'm not trying to revive an old thread but..
Personally, whether I prefer sub-titles or dubbing really depends on the medium and how well it's done. For instance, I really like 'DragonBall Z's' english dubbed versions to the japanese sub-titles because they are so well done. However, I also own and watch a lot of other anime that has english dubbing available, but I usuallyprefer the sub-titles. Usually that's because the english translation doesn't get the same quality of treatment that popular series, like DBZ, receive. Sometimes, companies focus too much on actual wording and not enough on properly conveying the emotions and ideas behind them.
Of course, sometimes ideas and jokes don't translate directly. So, forethought and a proper background in both cultures is nessesary to "fill the gap" in translation, so you don't have conversations being held with no translation at all.
Just my two cents...