Just about all of the old movie stars who served in the military are dead now. They made up most of the very famous/very good in the acting profession. The list linked below covers many of them.
There are many more: Paul Newman, Gene Hackman, Harvey Keitel, Humphrey Bogart (Bogart supposedly got his trademark scar from a shrapnel wound while at sea, leading to his characteristic lisp), George C. Scott, Clint Eastwood, Mr. T, Ice-T, Johnny Cash, Morgan Freeman, Chuck Norris, James Earl Jones, Dennis Franz, Rob Riggle and, Hey, Elvis Presley.
Maybe being Vets helped them become great.