I've read all of them. Suprynowicz's columns are IMHO excellent. A few are focused on extremely local Las Vegas issues, but most are about national issues. He also goes into rant mode every now and then, doing little more than tearing a new asshole for some left-wing weenie who made the mistake of sending him a letter opposing something he wrote in an earlier column.
Black Arrow is so-so. Very cartoonish. It's worth a read if you like that sort of thing, but you'd probably be better off checking it out of your local library.
Unintended Consequences is, of course, a classic among gun nuts, and deservedly so. The only negative, IMHO, is that the sex scenes make it inappropriate as a gift for some of my more religious friends.
ETA: if anyone has a way to get a digital copy of UC, I'd appreciate a link, too. I've been wanting to reread a few parts of it but my copies are in storage.