Normally super attacks are for the Shounen genre with things like the kamehameha in Dragonball or the Rasengan in Naruto, but oddly enough my favorite attack isn’t from something I would call Shounen. They just seem to make these “super attacks” work in a context where it fits but not be a part of that genre.
Count another one for Fate/Zero and Ufotable. My favorite attack ever used was the Noble Phantasm (aka his super move) for Rider. His Noble Phantasm is Ionioi Hetairoi which means Army of the King. During it Rider creates an alternate reality where every soldier who ever served Rider is reborn and is spawned to fight his enemy within the alternate reality. Also there is an awesome song that goes with his Noble Phantasm.