Shaw Jones
Although his role in JAG was a small one, Shaw Jones has kept on adding to his acting credits since then and may be known to some as Sam in The Letter, or as Leo in The Heist. More recently he played Robert Perkins in Blue, and Stringer in the film End of Sentence which starred Logan Lerman.
Guy Garner
Guy Garner was Lt. Tom Hart in JAG, and later played Anthony in An Assassins Tale, but regrettably, he has kind of disappeared off the scene since 2013.