I have found a dearth of high quality third party military bases in X-PLANE. I did find a fantastic one over at the .org.

McChord AFB is a joint Air Force/army base in Tacoma, Washington, about 50 miles south of Seattle. This base has an authentic feel to me from my Air Force days. The flight line is loaded with plenty of C-17’s, KC-10’s and a few F-16’s. Be sure to download the extra libraries indicated.

A solid effort from a French author and payware quality for free. Well worth the download for your modern jets. I flew the new F-35 from there. A great flight.