Well, I personally don't like any of the 4, but some of that is personal taste (the beverage part, grin). And I thought that the 'Old Men' book WAS a part of the Border Trilogy, was I mistaken?
Re the Bourne books, I personally distrust any book(s) that contain any plot lines involving any superagents and Save-The-World-From-Disaster scenarios. The closest thing to a superagent that I can 'believe' & recommend is Adam Hall's (pseud.) Quiller.
A deceased (I believe) author who wrote of an interestingly-repeating character is Donald Hamilton with his Matt Helm series. No save-the-world here, just a no-nonsense believable protagonist who uses his pragmatic, utilitarian weapons in a very competent and believable manner. Kinda formulaic, kinda not, but at least Hamilton was an outdoor man who was familiar with guns, hunting, and the actual real-world effects of knives and bullets.
Thanks to all for your suggestions, my book allowance will be prespent for the next few weeks at least!
Regards, Joe