Mine top 5 are, in no particular order:

• The Martian (I prefer this to PHM as I feel it’s a story that is a realistic possibility)
• The Interdependency trilogy (I wanted more books, more time in this universe)
• Expeditionary Force (OK, it gets a bit samey in the middle books and there’s the dire full cast novella, but I feel they’re great overall. Not finished the series yet but heard some dislike for the final book)
• Bobiverse (I was hooked from the beginning, yes book 4 is a bit of a departure)
• The Expanse (Simply the best hard sci fi, grounded in reality, but the final few books do go a bit off tangent)

Honorable mentions to:

• Recursion (Just such an intriguing concept)
• Dark Matter (I wish I could listen it again without knowing the plot)
• Old Mans War + most of the sequels (I’m a big fan of all of John Scalzi’s work)
• Project Hail Mary (OK, this could have been in the top 5 but I prefer The Martian!)
• Hell Divers (A great start but got a bit silly in the last few books)

I could name so many more, but seeing as I’m listening to about 30 books per year it’s hard to remember them all.