If I could change anything about a Zelda game...

1.) I'd restore the original game manual and ingame text for Link's uncle in the GBA version of "A Link to the Past". ("Zelda is your..." responsiblity now? Anyone? Seems like so much fuss over such a dumb little thing and the new text just seems forced)

2.) I'd change the backstory to "The Wind Waker" to be more ambiguous so that it could be viewed as the chronological "end" to the old series. (Since the idea of a new Hyrule being named after long forgotten locations and at the same time being in 'generally' the same places just seems dumb to me)

3.) I would alter two pieces of text in ALttP: The essence of the Triforce would no longer say Ganon was "totally destroyed" and the caption for the last scene with the Master Sword would just say, "The Master Sword sleeps again..."

4.) I would add in the original 'tales' of Mountain People apparantly mentioned in the SNES version of ALttP.

I suppose aside from those small twiques to the text in some of games I would not change a whole lot. They are very well made as they are and changing them over such small things is nit-picking.

OH!

I would give Link brown tights and sleeves in OoT because I think they look better.