For reasons too complex to elaborate on, I've found myself sitting atop a king's ransom of credits for free audiobooks (it was a billing error that screwed me out of a few hundred dollars that's been corrected after I saber-rattled, lest anyone think I'm shilling). I've got about 25 audiobooks' worth of credits that I need to burn through before I can accumulate any more, so this calls for a spending spree.
I love roman history, and based upon recommendations from /u/Celebreth in other threads I've shoved Adrian Goldsworthy's full catalogue into my shopping cart. Can anyone point me towards any other good stuff (or away from any bad stuff)? Roman history is best, but anything is fair game.
I recommend any classes from the Great Courses by Elizabeth Vandiver. She's great. Since you like Roman history, you should start with her course on The Aeneid. I'm sure you'll like it, and then you can decide on other courses about Greek and Roman mythology. While The Aeneid isn't truly history, I think it will be fascinating for anyone interested in Roman history. For that matter, afterwards, you might want to check out her lectures on Herodotus, the first historian.
If you find you like the Great Courses format, check out their WWI and WWII overview courses.
Are you specifically interested in non-fiction, or historical fiction as well? Because I can certainly recommend you non-fiction that is available as Audiobooks, but I read those, so can't attest to the narration. For actual audiobooks I stick mostly to fiction.
Not sure if it fits your criteria, but I absolutely loved Our Magnificent Bastard Tongue by John McWhorter. It's about the history of English, and how it evolved, and how we know how it evolved. It gets a lot into pronunciation, so I don't even know how it would work in print. Anyway, I loved listening to that one.