Cessna A-37 Dragonfly (South America & Africa) AC-47 Spooky (Colombian Air Force) B-57 Canberra (if you include the 3 NASA operate) Lockheed C5 Galaxy Northrop F-5 Freedom Fighter OV-10 Bronco (Philipines) Lockheed U2
US Department of State and some civil operators in the USA and Canada still operate the CH-43 Sea Knight (Chinook lite) they lost 109 of them in Vietnam.