I think Susanoo is the best jutsu, because it protects the user (and during the transformations the layers for the defense are gained) and it has transformations, at the last transformation it has muscles and it has different weapons on different users. In Itachi's version, Susanoo has Yata Mirror (that has all the chakra natures, and if you attack it with a jutsu that belongs to a chakra nature, Susanoo changes its characteristic to that chakra nature making the technique that it receives to be uneffective) and it also has Totsuka sword. Zetsu stated that Yata mirror combined with Totsuka sword makes the Susanoo invincible.
On Sasuke versions, Susanoo has a bow and chakra arrows (that is nearly impossible to escape them) and it also has a sword.
Susanoo is also called Tempestuous God of Valour, it also make an Amaterasu shield( Sasuke version).