Recently read "Empire" by Orson Scott Card; it was pretty good, though not as good as much of his other stuff. It's got some sci-fi elements, but it has good political thought in it and it should appeal to anyone who likes reading the SHTF-type stuff that's found here on THR and elsewhere online.
Anything by WEB Griffin should be good. I've got a couple of his books on my shelf; I like the ones about Marines (Saga of the Corps or something like that - they're a series).
Clive Cussler is pretty good, too, if a bit "teenager" in his writing level.
Pick up some Peter Maas books for a really good read - he's got wonderfully developed characters and indepth stories written with wit and sarcasm. I'm reading "Father and Son" now; I'd have to say he's one of/my favorite author in the genre.
Avoid the Mack Bolan books if you want something with a story; they're basically just gun porn and, while they'll distract you for a while, I sometimes have a hard time reading them because there's no character development (they're serials). Well enough written for what they are, though.
Also, "Enemies, Foreign and Domestic" and "Domestic Enemies" by Matthew Bracken are good, though I'd hesitate to read them on a plane these days (due to the topic, the cover art, and title), unfortunately; Bracken is a member and poster here on THR.
http://www.enemiesforeignanddomestic.com/
