Loaded words, I know.
The greatest challenge I hear from book group leaders is getting more male readers to attend. Aside from snatching dudes wandering the DIY section of the stacks and plopping them in the middle of a book chat, facilitators consider the reading selections to entice men to the book group.
If historical nonfiction is perennially popular with men who read, then military memoirs could be considered biblio-catnip. USAToday collated a list of memoirs from NavySEALS. There’s an expanded list as well. Full disclosure: I contributed a comment to one of the stories. I said these books have been very popular lately and are good gateway titles into nonfiction for readers of hard-boiled mysteries.
That said, there’s a number of discussable titles on these lists that both genders will enjoy.