Using more than a few editions of classics in Latin is a key to make the reading experience feel smoother, especially if you are an autodidact. In terms of Dē Bellō Gallicō, we are more than lucky to have dozens of editions prepared for various needs of students by prolific editors, interpreters. Since I myself am currently reading Caesar for the betterment of my Latin and it constitutes the bulk of my current intensive readings, I thought to myself that it would be nice to make a list of my favorite editions of Dē Bellō Gallicō that I use during my personal studies. and share it here.
1. Out of all the editions I have come across James Finch's edition is by far the best for it is flexibility for different uses. This edition is completely parsed, word by word, line by line including references to master works of Latin grammar, in case you want to understand in depth the construction of the words, phrases and the sentences. On top of that, Finch's edition doesn't only have literal interlinear translation but also elegant marginal translation, to better understand the text as a text. The Latin text in this edition is in the original order.
2. Another edition with lots of notes is Geoffrey Steadman's edition. It has facing notes besides vocabulary which is placed at the bottom of each page after the original text. Steadman's copies are free to download on his website. If you want physical copies, they are sold on Amazon.
3. Similar to Steadman's edition is Hans-Friedrich Mueller's edition. This edition's pros compared to that of Steadman's is Mueller's usage of italics to make the intricate text more readable for a modern reader.
4. Reading an original classical text in Latin compared to reading, say, Familia Rōmāna of Hans Ørberg is especially hard due to very intricate construction of sentences. Where does the main clause start, where does the adverbial clause end, which subject is for which verb, etc. Thus, Jean-François Mondon's Syntactically Parsed Reader is of Dē Bellō Gallicō is a must have. 5. Another edition which helps with the confusion such intricate sentences bring about is Frederick Holland Dewey's Students' Interlinear Translation of Caesar's Commentaries on the Gallic War. That which makes this edition different compared to others is the modifications made in the order of words. These modifications made, the text is rendered much more comprehensible to anyone who have a working knowledge of the English language or languages following the SoV construction.
6. Hans Ørberg prepared an edition of Commentāriī Dē Bellō Gallicō. It is especially great for sight reading if your Latin is competent enough work through the text via tips given in Latin only.
7. Reading texts in languages you are comfortable with before you read the text in your target language renders the text in the target language comprehensible. Thus you can render texts that are incomprehensible rather comprehensible by first comprehending them, that is, by reading them in your source language. In the case of Latin, Loeb Classical Library comes to the rescue. H. J. Edwards edition of The Gallic War with facing parallel translation is good to have at your disposal.
8. An important of language competence is fluency. Verbal exercises are important part of fluency not only in speaking but also reading. L. Sauveur's edition called Talks with Caesar is a sui generis one in its style. This edition makes you have conversation with the text by providing both the questions and the answers. The amount of repetition in this edition makes it perfect for different methodologies of learning and teaching. I personally study it verbally once I have a working comprehension of the actual text. It brings the study to its, so to speak, fulfillment.
See the attachments to download the editions that are without copyright issues.