Of course, it’s more convenient to have someone synchronize them for you—also called timing—so that the subtitles appear right at the time the person is actually talking. Checking the original translation and an additional editing stage wouldn’t hurt either. Nobody is perfect. Mistakes are bound to happen. Have more people work on it and the amount of errors will be minimized.

Here’s what I want to know:   What’s the most important thing in a fansub for you?

Translation/Translation Checking/Editing involves a person fluent in Japanese who translates the dialogue/signs into English. Someone else checks the translation for errors,  a 3rd person will try to make the English script as error-free as possible and additionally try to make the “flow” of the English perfect.

Timing
Perfect timing means you won’t even notice that there are subtitles—you’ll think of them as a part of the video. Bad timing interrupts your pace of reading and can be very annoying.

Typesetting/Karaoke
There’s nothing wrong with having fancy karaoke or advanced AFX typesetting if it fits into the anime. If it does not stand out, or if you think it’s part of the video even, then and only then, is the typesetting done well. If a karaoke can make a horrible song sound really amazing, then the karaoke is good! :P

Quality Check
Even the best in fansubbing make errors—and not as few as one would think. In order to avoid releasing error-ridden episodes there are Quality Checkers. There’s (nearly) no people who can be good at spotting “all” kinds of errors. Some are good at spotting timing errors, others at spotting editing errors etc. So basically, there should always be at least 2 or 3 people QCing the episodes.

Encoding
Watching crystal clear anime on a 42″ display must be really awesome. It sucks if the encode is bad. If the encoder knows what he’s doing, you’ll receive the best video and audio quality with the best compression ratio possible.

There’s also other stuff like subtitles styling which deserve to be mentioned. If the font is not readable—especially when it’s hardsubbed (fused with the video)—it can be a pain in the ass to watch the episodes cause there’s no way to change it.

I’ve talked to many people, read many comments or reviews on AniDB, and I’m also speaking from my own experiences. Everyone seems to have their own definition of what’s “good.” What I’m interested in is what the majority of you think is the most important in a fansub.

I’m interested in your opinion. Take part in the poll! State your opinion! Why do you think X is most important? Don’t forget to state your reason!

Edit 21.10.2009
Additionally, what do you think about karaoke? Is karaoke fine no matter if it’s harsubbed or softsubbed? Does it have to be fancy or should it just fit into the video (no matter how simple the effects are)? Or would you prefer no karaoke effects at all and just timed lines so you can sing along? Or just cut out the opening and ending and release two versions — one with karaoke and one without effects (ordered chapters).