I also like "The Cowboys" however it is outside of the 25 year limit.
Others that come to mind are Kevin Costner's best movie, "Fandango".
"Rudy"
"Big Red One"
"Breaker Morant"
"Das Boot"
"Shenandoah"
"The Man Who Shot Liberty Valance"
"A big Hand For a Little Lady"
"In Harm's Way"
and one of my favorites of all time..."Spencer's Mountain".
Most of these are outside the 25 year limit, but St. Ralph and Spencer's Mountain are nice bookends.
/johnny