These were one of the original companies bringing
anime to the english speaking world.
One unique feature of AnimEigo is their liner notes. As well as providing a translation of the script of the anime they also attempt to provide a guide to the cultural and in-joke etc. references within the material. These liner notes are very interesting, and in the case of some items such as "Otaku No Video" and "Urusei Yatsura" they are essential to properly enjoy the show.
They are very proud of the quality of their subtitling and wrote their own software and created their own font. They always used different colours for different characters and time the appearance of the lines very carefully.
Originally they only did subtitled anime (partly for economic reasons and partly because of the purist streak in the anime fans at the time). However in recent years they have been releasing both subtitled and dubbed and with the move into DVD they can do both in one package (without recording it twice - I do have some of their hybrid LDs).
When they translate they produce two translation:
A fairly literal translation for the subtitles
A much more 'anglisised' version for the dub
As well as VHS they have produced a large number of LaserDisk versions of anime (where possible going back to original master and producing a very high quality transfer). This company (whom I do not work for) is known for the quality of their product (unusual in an industry that includes Streamline Video).
They are now starting to produce DVDs. Their release of "Bubblegum Crisis" was done by a third party and was not very successful. However they are now getting ready to release their first inhouse produced DVD ("Urusei Yatsura" TV vol 1-5) and this should be much better.