Nominate! for the Curmudgeon's Book List

The First Reader is on leave from work, and has departed for his parent's house. He will be down there, returning the favor for them raising him. However, we both anticipate long hours of quiet time, where he will have little to do besides read. 

So... 

I need to make a very special book list. I can feed his Kindle library from home, and plan to. But he is going to run out of reading material and I'm going to run out of ideas! Help us, reader friends! You're our only hope! 

Just to summarize his tastes: he reads a lot of Louis L'Amour, David Drake, John Ringo, Peter Grant, anything Baen Books put out up until the last 5 years or so (and much of that, but there are new authors neither of us are familiar with). His latest binges have included all of Jim Butcher's Dresden Files, Glen Cook's Garrett PI series, and Jerry Boyd's space salvage crew. 

Things he doesn't like: romance as a main plot. He's fine with it as a sub-plot, but as a major theme it does not float his boat. He doesn't read gray goo, or horror, and he's not a fan of most YA. 

Ideally, I'd love to hear about books in the Kindle Unlimited library, as I have a more limited budget than usual (this is unpaid leave for 6 weeks. The family income literally just halved. We're going to be fine, but I'm budget-conscious).