So any other decent one man army ex-marine/green beret vietnam vet type movies?

So i was watching Rambo, finally first blood and the 2nd one, and i was wondering if there were other movies like that that dealt with similar themes, and idea. Then someone recommended the chuck norris missing in action series, was kinda like rambo. so, yea i was wondering if there where anything else out there like that. first i would like you to recommend movies where vietnam has some significance to the character. but, if you don't know any other recommendations are ok.