I like all the swords in MM, too bad you can only get stuck with one at the end(Guilded Sword) but I love the Razor Sword(3 hits and its gone, wow, uhorrible Nintendo), the Great Fairy Sword(which stupidly it's a C-item) and the Fierce Deity sword.
I also like the good ol' Master Sword(especially the Wind Waker design) and Giant's knife.
Oh and wheres the love for Spirit Tracks? The Lokomo Sword has got to be the most bad-as* designed of all the swords in TLoZ!
I voted for the Biggoron's sword because 1 it is double the size of link and 2 it does twice as much damage as the master sword. this sword made ganon easier in Ocarina of Time and definitely made dark link look like a joke.
my second favorite sword would be the double helix sword, Why? because it shoots streams of energy (but cannot kill a Big octo).
Looks like another 4 swords are missing..we got the:
the razor sword
the phantom sword
the lokomo sword.
out of those four i choose the phantom sword because it is beastly.