Which is ironic, as the US military is now the largest user of Hawker Hunters (albeit through a civilian contractor).
As has already been mentioned, the Hawk/T45 Goshawk is definitely worthy of being on that list (in production for 45 years, 1000+ built including about 300 for the US Navy). Ironically it got some stick in the early 1970s for 'duplicating' the joint European Alphajet, but is still in production nearly 30 years after the last Alphajet appeared.
The Gnat was also quite successful. The Indians seem to have used it to great success in their wars with Pakistan.