He who fights with monsters by shirtaloom & Travis Deverell
In case you don't know, Shirtaloon is the pen name on web, Travis Deverell is the name on amazon. Same aussie.
Among the suggestions already made:
Dungeon Crawler Carl (DCC) is very good, I concur. Dark Humor at every corner (Matt Dinniman loves dark settings). Still ongoing, the series hasn't ended.
The Ten Realms is basically a cultivation series masquerading as LitRPG, as it's often the case these days. Just add guns.
Cradle is pure cultivation, no LitRPG at all;
Arcane Ascension is a magic series that people call LitRPG-adjacent because people get a "class", but there are no stats or anything there (and the other novels in the series essentially confirm that those classes are essentially crutches that replace a proper attunement to magic). The
Bobiverse is classic scifi.
Everybody loves large chests is a bit tamer on amazon/audible than the original web series. Fair warning: smut, SM, rape, gratuitous violence abounds. One of the main characters had so much self-hate after traumatic rape she essentially turns herself into a full cyborg. Series is over on web, still being published.
I'm going to add some stuff that you might find interesting and that I know has audio (I don't do audio):
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Dawn of the Void (Phil Tucker), completed trilogy. People hated the ending, and Phil confessed he decided abruptly to wrap it up rather than string the series along. But it's a good system apocalypse.
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Return of the Runebound Professor (Actus), recent ongoing series (I think only 2 books are out on amazon/audio). A non-litRPG progression fantasy featuring what is technically an Ancient Lich. That also happens to be a former teacher of music who plays darts.
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Speedrunning the Multiverse (Adastra339), complete series. Another cultivation series wrapped under a litrpg paper. Bored god is speedrunning the entire ascension progress from zero to god when things go sideways.
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Defiance of the Fall (JF Brink), ongoing slow-ass ultra-long series (#12 already there, #13 coming out this month). Lots of people love it, lots of people got bored by it (me included), your mileage may vary.