I've seen this is a matter of debate in Anime communities, Subtitles vs English Dubs. I"m not really that much into groups or forums, so I don't get into great discussions over these things. But recently my friends asked me the same question. One is an avid sub fan, he likes hearing the Japanese voices. My other friends enjoy subs because its the original, or true, form of the show. Some that have tried anime think its awkward to listen to Japanese at home with their family around, so they stick to dubs. Personally, I prefer English dubs because its easier to connect with the characters (and I can't follow the emotions in Japanese voices well at times). I don't have anything against subs, I've seen plenty of them, but if I'm given the option I go for dubbing.
And of course I have an attachment to several voice actors, especially FUNI's regulars, and seeing them fill roles in separate series makes me squee like a teenage fangirl upon finding them. But it goes for people with Japanese voice actors as well, and I can't really say that I'd have the same opinion if I'd watched subs of my favorite series first. A great example of this is the Shakugan no Shana series. The first dubbed release was done by Geneon, before FUNimation licensed and started dubbing the remaining seasons. After the shift in voice actors, I often found myself thinking "would the original cast have done this better?"
But what if the roles had reversed? What if the voice actors that did season 2 had done season 1 and vice-versa? Would I think the same thing? I can't honestly say, because first perceptions are incredibly important with these types of opinions. That's my biggest complaint among my purist friends who believe shows are better because its in its original form it was made for. For all we know, anther Japanese cast could have done much better or worse, just like the English versions. Although I do admit the fact that they are tailored for Japanese does give it a definite edge, English can be adapted to suit it well even with that in mind.
Which leads to the other point: that some shows simply don't come across well in English versus their Japanese counterparts. While this is true and sometimes prominent, there are also a small number of shows that are better in English, so it can go either way.
So in my opinion, it comes straight down to personal preference.
So what do you think? Are there any points that greatly make one better than the other? Please refrain from unfriendly comments, I just want points to discuss with my friends and you with yours.