Not necessarily the strongest or most overpowered, just which one you think has the best visuals.
My favorites would be Bijuu-Dama Rasenshuriken, Twin Lion Fists, Itachi's Yasaka Magatama, and Wood Dragon.
Rasenshuriken, bijuu mode, sasuke's complete susano'o, Madara's perfect susano'o, itachi's complete susano'o, planetary rasengan, sage mode naruto, sage mode hashirama, thousand hand buddha statue, Tsukuyomi, Amaterasu, shiki fuujin, sannin summons, jiraiya sage mode, shinra tensei, chibaku tensei, asura path, king of hell, base chidori, chidori spear, Kirin, 3rd kazekage magnet release, 64 and 128 palms, air palm, Asuma's katon, konan's 6 billion paper bombs, konan's paper jutsu, 8 gates, twin lion fists, yin release: lighting claw, juubi's storm technique, black lightning, shadow imitation stitch, shino's giant parasitic insects, hebi sasuke curse mark 2, orochimaru's hydra technique, kidomaru's bow and curse mark 2, yasaka beads, Uzumaki chakra chains, byakugou, ice mirrors, gudou damas, jinton, liger bomb, yoton rasenshuriken, black chidori, crystal release, acid bubble.
