Hands down, US Fletcher class destroyer. 175 built, the next two US destroyer classes based off of it. It was the destroyer that screened the US carrier battle groups. 5 duel purpose 5" guns, numerous AA guns, 10 21" torpedo tubes (only effective after the US solved its torpedo problem). speed, 38 knots. a true warship. also, one could argue they won the war for the US. It was basically the Navy’s version of the Sherman tank. plus, the last one was decommissioned in 2001, so a life of 57-59 years depending on when it was commissioned.