The only none American types (or American build) is the Hawk! – Oh yea and now the new Merlin helos!

What about:

Dassault HU-25A Guardian

http://www.airliners.net/open.file/674305/M/

Aerospatiale HH-65A Dolphin

http://www.airliners.net/open.file/684405/M/

De Havilland Canada UV-18A Twin Otter

http://www.airliners.net/open.file/729580/M/

De Havilland Canada C-7A Caribou

http://www.airliners.net/open.file/578177/M/

Embraer R-99

(ordered but not delivered yet so no pictures available in US markings)

Shorts C-23B Sherpa

http://www.airliners.net/open.file/671528/M/

I’m sure there are others but those are what I could come up with off the top of my head.