Significance
The Battle of Leyte Gulf was very significant because it destroyed the Japanese naval forces, cut off needed supplies from reaching Japan, was the first battle the Japanese used kamikaze planes, and was the largest and greatest naval battle in WWII and all of modern history.
Supporting quotes
"The strategic result of capturing the Philippines will be decisive. The enemy's so-called Greater East Asia Co-Prosperity Sphere will be cut in two. His conquered empire to the south comprising the Dutch East Indies, and the British possessions of Borneo, Malaya and Burma will be severed from Japan proper. The great flow of transportation and supply upon which Japan's vital war industry depends will be cut as will the counter supply of his forces to the south. A half million men will be cut off without hope of support and with ultimate destruction at the leisure of the Allies a certainty. In broad strategical conception the defensive line of the Japanese which extends along the coast of Asia from the Japan Islands through Formosa, the Philippines, the East Indies, to Singapore and Burma will be pierced in the center permitting an envelopment to the south and to the north. Either flank will be vulnerable and can be rolled up at will."-General MacArthur (Chapter 8: The Leyte Operation, http://www.history.army.mil/books/wwii/MacArthur%20Reports/MacArthur%20V1/ch08.htm)
"Our defeat at Leyte was tantamount to the loss of the Philippines. When you took the Philippines, that was the end of our resources." -Admiral Mitsumasa Yonai, Japanese Navy Minister (Leyte Invasion, http://www.dtic.mil/dtic/tr/fulltext/u2/a145291.pdf)
"Our defeat at Leyte was tantamount to the loss of the Philippines. When you took the Philippines, that was the end of our resources." -Admiral Mitsumasa Yonai, Japanese Navy Minister (Leyte Invasion, http://www.dtic.mil/dtic/tr/fulltext/u2/a145291.pdf)