WoL's Bastard Sword, Zidane's Mage Mashers, Firion's Blood Sword, Bartz's Brave Blade are all leagues above Tidus' stupid water sword and the abominations that are the buster sword and squall's gunblade.
Any sword that is similar in size to the buster sword, as in hugely impractical, is automatically disqualified as being the best of anything by how fucking stupid it looks given it's size. Masamune, while thin, is also just as stupidly long and thus also shit.