I nominate The Big “E”, CV-6, The USS Enterprise. She served all of WWII. She was involved in every major battle but one in the Pacific.
Bad weather delayed her return to Pearl from December 6th so she was not in port when the Japanese struck. She was near enough to launch Squadrons however and so participated even in Pearl Harbor. She escorted the Hornet on the “Doolittle Raid”. Was a major part of the great victory at Midway, though the Yorktown did at least as much in this battle before sinking.
This left only the Enterprise and the Hornet as the Pacific Carriers.
At the Battle of the Eastern Solomons, the US Navy triumphed but the Enterprise was badly damaged. Her Damage Control Parties patched her up well enough and quick enough to return to Pearl. Here they managed to repair her in just 36 days. She formed up with the Hornet again for the Battle of the Santa Cruz Islands. She took two bomb hits this time but remained in action and recovered a significant number of planes and crewmen from the Hornet that was sunk in this battle.
This left The Big “E” as the sole defender of the Pacific. She raced from battle to battle like no ship had ever done before here. Often sailing out with repair crews still onboard and at one point with 75 Seabees onboard aiding in emergency repairs. So from October 26, 1942 to the Summer of 1943 she held the line as the only US Carrier in the Pacific.
Her exploits continued throughout the war, fighting the entire war. On at least 3 occasions the Japanese reported her sunk. This picked her up the additional nicknames of The Grey Ghost & The Galloping Ghost. She fought in the Battle of the Philippine Sea, Battle of Leyte Gulf. She was the first ship capable of night flight operations and hit Luzon & Tokyo, striking shore targets and shipping from Formosa to Indo-China including an attack on Macau, supported the Marines in the Battle of Iwo Jima
In all she received 20 Battle Stars in WWII, the most and the most in our history at that point. Here is the complete list of her Battle Stars. The USS New Jersey eventually passed her but not until the 1990s.
Post war she was part of the massive Operation Magic Carpet in both the Pacific and the Atlantic returning servicemen home from foreign theaters.
Very sadly she was scrapped in 1958 instead of becoming a museum ship. But the name rose again in the form of our first Nuclear Powered Carrier, CVN-65 The USS Enterprise. Then a certain Gene Roddenberry named his Starship after CV-6, a “heroic ship” as he thought of her.