Console and handheld games included.  But mainline games ONLY, so no CD-i games please.

My choice is between Spirit Tracks and Link's Adventure.

I would say Wind Waker for me. Even though I like the game it's the only Zelda game I left. Usually once I start a Zelda game I don't stop until I finish them but not with this one. I'll get to it eventually though.

Gotta be between Zelda II and Wind Waker, though Skyward Sword is in the mix now. I hated the switch to side-scroller at the time and the music was weird, but I now look back on The Adventure of Link fondly. I like the expansiveness of the world, multiple towns to go to and so on. WW, in the same way, I didn't touch because of the toon look, but now I've picked it up in HD and it's a really great game. SS I think may eventually be looked at as the worst game. It's OK, but it really doesn't push many boundaries other than in controls. Z2 and WW were odd ducks, but very good games in their own right.

Zelda II for sure, and personally its one of my faves because of its differences

Zelda II. Whoever thought of making you hit the EXP numbers to get them, needs to be shot.

Windwaker, Twilight Princess, Spirit Tracks, and Phantom Hourglass

All of the CDI versions

In terms of official versions, I guess WW and the DS games with that style... I loved those games but people want realism over art style apparently

Phantom Hourglass by far. Anyone who thought using touch controls for basically everything was a good idea needs to be fired. The game had some clever puzzles, but other than that there's nothing really good about it.

The CDI games of course. If you mean proper games probably Zelda 2.

Zelda the Minish Cap, just didnt do it fo me.
I like DS Zeldas to an extent.