Rav Hirsch was- and is well known for his extensive literary canon, which ranges from Torah, to tefillah, to hashkafah. However, today there are a good number of English editions of some of his works. Which ones, on a book-to-book basis, are widely considered the most accurate and legible?
- Hirsch Chumash - typographically and linguistically, the Feldheim is more legible than the Judaica Press. It was newly translated (the JP version was translated a while ago), so it will make for an easier read than the older version.
- Nineteen Letters - can be found here for pay (good print) and here for free (older translation, older print; still legible though). A back-and-forth between a rabbi and a young man (both fictional) on many of the basics of Judaism.
I can't comment on the other editions, but Rabbi Isadore Grunfeld's translation of Horeb is excellent, as is his (nearly 100 page!) introduction. I consider this sefer a must-read for all Jews, as it is a unique, comprehensive and compelling philosophy of Judaism, as well as a concise summary of all halacha relevant to the life of an observant Jew. The sentences are long and flowery, and thus take considerable concentration to follow. But I can't imagine how a faithful translation could cut his poetic 19th-century German sentences into 21st-century style sentences.