So, today I tried watching a 4kids dub for the first time. I went into it expecting it to be absolutely awful... And I was pleasantly surprised by how much I enjoyed it. I was also talking with my boyfriend about dubs vs subs today, so I was just wondering...

In your opinion, what's most important for a good dub?

I know that a lot of people care about having an accurate translation, and to an extent, I agree. But honestly, what I think is more important than accurate translation is that the overall tone and spirit of the show is kept.

For example, look at Panty and Stocking with Garterbelt. The original Japanese version of that show is meant to be filthy and raunchy, and while the dub's dialogue isn't always the same as the original, it definitely keeps with the spirit of the show. It relies on creative vulgarity/offensiveness instead of screaming random profanities in a foreign language.

Or the aforementioned 4kids show I watched today, Magical DoReMi. The original was a lighthearted comedy for little girls... Which is exactly what the dub is. Sure, there was some Americanization, but the general spirit of the show was much the same, which made it quite enjoyable for me.

The other thing I think is important in a good dub is, of course, good voice acting. And honestly, voice acting is usually the reason why I tend to opt for the Japanese version. But I've watched shows in Japanese where I didn't care for the voices, so really, it's not that big of a deal.

Any thoughts?

I agree. Dubs need to have the same heart and soul as the original. To me as long as it keeps the same story as the original than it's good in my book. It doesn't need to keep word for word. 

For example:

I can still watch 4kids's dub of Pokemon. Not because I watch it as a kid, but because they put a lot of heart into it and the story was still there (even though they had some mess ups. XD). I met some of the voices actors two years ago and they really love what they did back then. They said in their panel that it makes them happy to talk the fans who grew up with the old dub. 

I can't watch Cardcaptors (CCS's dub) anymore because the story was mangled despite it being part of my childhood. Nelvena ruin the message of the show by trying to turn it into a boy show. The only thing I can watch is the theme song because it's catchy as hell.

As for voice acting. I judge them like the Japanese voice actors. There are bad actors in any country. I stopped watching some animes because I couldn't stand the Japanese voice actors. I can't stand super high pitch voices. I don't get why people think that's cute...

I won't watch a dub if they heavily censor things. I'm against censorship.

I'd describe a good dub as one that's well acted and accurately captures the intention of the original work.

That doesn't necessarily mean being completely faithful is always the best approach. Panty and Stocking's dub is absolutely amazing and Steins;Gate, despite some pretty drastic changes to the original, still manages to communicate the same message. You can even improve on the series by changing a few things. High School DxD is still a bad show no matter what language you watch it in, but the English dub throws in a few jokes of its own every now and then which are all way more funny than anything in the original and overall make it a more enjoyable viewing experience.

Of course there are certain cases where a more localised approach doesn't really work. A Certain Scientific Railgun is a show that could have worked in English but Funimation's direction just isn't compatible with the series. Also, being faithful can work for some shows too. The dialogue in the Lucky Star dub is laden with all sorts weeaboo slang and for some reason it works like a charm. What isn't good is when they just regurgitate the subtitle script and change a few words so it can match the lip flaps. Which is a mistake often made in bad Sentai Filmworks dubs like Penguindrum and Little Busters.

Subtitle scripts do not sound like natural conversation when read aloud. Changes have to be made. And if you're making the dub for young children, you also have to censor certain things and make everything easier to understand for kids who don't understand Japanese culture. 4kids dubs are made 'for kids' and as a kid who grew up on Pokemon and Yu-Gi-Oh I'd say they did a good job. They may have slipped up a bit with One Piece but you can't win 'em all.

There may be a lot of people on the Internet who don't know the first thing about how the whole dubbing process works but stubbornly insist that they know better than people who've been in the business for over a decade. But at this stage, most English dubs are of pretty decent quality. There's been a lot of trial and error to get to this point but by now I think it's safe to say that most of the companies who dub anime know what they're doing.