> In the case of Ergo Proxy, the additional notes in the fansubbing really helped understand the bigger dialogue. Without it I probably would not have held that particular show in has high of a regard.
Ergo Proxy in particular sticks out to me as a case where the fansubs were superior to the commercial release. The DVDs didn't have any of those notes, and they added a lot to the show.
I've seen Ergo Proxy with 3 different versions of subtitles (regular, and at least two fansubs) and I've always dreamed of combining the scripts used because none of them quite voiced things perfectly alone, but snag a few conventions from one or another of the versions and use them throughout and suddenly the whole show would just be so much more accessible and clear.
Fansubs are almost always better than the commercial releases, because if the show is even relatively popular (and shows that get official releases usually are), a group will edit the official release's script.
You honestly can't beat the time and passion fans will put in. Most of translators working for places like CrunchyRoll get paid per release, so they have no incentive to spend more time on a release and give it a quality translation. On the other hand, fans have already read/played the source material and will use background knowledge to properly translate the material.
One problem with commercial releases is overlocalization. Watchers too have background knowledge (Japan mythology or food for example) and sometimes there's a dissonance in what you hear and what they mean. Pokemon calling rice balls donuts[0] comes to mind.
Overlocalization (and censorship) happened much more in the much earlier days of English anime (like the time when Pokemon came out). There isn't a real lot of that now because the fanbase wants true to the original translations. I have been out of the anime loop for a while now but that is my understanding. The NA release of Nausicaä of the Valley of the Wind comes to mind - it was released as Warriors of the Wind and was a total bastardization of the story. Miyazaki was incredibly dissatisfied with it so he adopted a "no cuts" policy for any future translations of his work. Apparently (so the rumor goes) when the English release of Princess Mononoke was being worked on they requested permission to change it in some way. The response from Studio Ghibli was a package containing a katana with the message "No cuts".
Ergo Proxy in particular sticks out to me as a case where the fansubs were superior to the commercial release. The DVDs didn't have any of those notes, and they added a lot to the show.