The Kokiri Sword From Majora's Mask, Because You Don't Have To Upgrade It, You Can Keep It As The Kokiri Sword, So In Retrospect You Could Beat The Entire Game With The Kokiri Sword, Which Just Shows How Important That Starting Sword Is.
The Wooden Sword from Twilight Princess. It's high on my list because the concept beyond this starter sword is the most inventive to me. Overall, though, I like the Ordon Sword better, for when the adventure in TP truly "starts".
I also like the "It's Dangerous To Go Alone" Sword from the original Legend of Zelda because of that nifty line. X3
The Kokiri Sword (I think that's the name of it) from Ocarina of Time. When I found that sword all on my own (because men don't accept directions or read signs) I felt like a total BAMF. I slahsed every blade of grass in my sight and tore apart all signs! To bad you couldn't kill Fado (the stupid Kokiri blocking your way), he's a bigger jerk than Ganon in that game.
The Ordon sword was good. It was my favourite starting weapon in appearance, the only problem with it over the Goddess sword is that it does not shoot skyward strikes. The Goddess sword is nasty and short in appearance but I know which one I would rather have, who needs length when you can get enemies from afar.