Well, this source I've looked at isn't during your requested time period, but I've found it very interesting. It is called De Agri Cultura, by Cato the Elder. It is essentially a handbook on animal husbandry and agriculture (the book is where the term came from), and it includes stuff like recipes and food preservation. I find it really interesting to try and make one of the recipes from it. Here's a link to a digital copy of it: De Agricultura by Cato the Elder.

Another source on foods (if your interested) is what we call Cookery and Dining in Imperial Rome, which was written or complied by Marcus Gavius Apicius. It includes one of the earliest recipes that could be called a "hamburger," and also provides some interesting information on the 1st Century, as well as the differences between Classical Latin and Vulgar Latin. Here's yet another link: Cookery and Dining in Imperial Rome, by Apicius.

Lastly, one book that I had to read for my Roman class was The Twelve Caesars, by Suetonius. It was written in the 2nd Century, and is a ruler by ruler biography of the first eleven Emperors of Rome, and Gaius Julius Caesar. Here is my last link for you: The Twelve Caesars, by Suetonius.

Sorry I didn't have anything from the Principate or from Commodus' reign.

For the imperial period, satires might be something you haven't considered as a primary source, but have some info on contemporary life. Some writers of satires include: Horace (1st century BCE), Persius (1st c. CE), and Juvenal (2nd c. CE). Similarly, Seneca the Younger (1st c. CE) wrote prolifically on a lot of subjects, but I recommend his Apocolocyntosis, a satire about the death and "apotheosis" of the emperor Claudius. The title means the "pumpkin-ification", and even though Claudius does not actually become a pumpkin in it, it jokes about his death and afterlife. Seneca's Letters would also be an good source to consider, as would the pseudo-Seneca play Octavia about Nero's spurned wife.

If you are interested in Marcus Aurelius, Galen the medical writer wrote a lot and also was his doctor, so he has interesting anecdotes about treating the emperor, as well as many medical works. He also accounts for about 10% of all the surviving ancient Greek we have. R.J. Hankinson's introduction to the Cambridge Companion to Galen, "The Man and His Work," has a nice overview of Galen's extensive writings.

For the later emperors (including Marcus Aurelius), you might enjoy the Historia Augusta, which is written in biographical style imitating Suetonius. Whoever wrote this credited different authors to the different biographies, although it was almost certainly written by one person. There are a lot of mysteries about its origin, but it's colorful and gives some insight into the later period.

My general advice is don't be afraid to delve into different genres.