For me, it's a toss up between Wind Waker and Majora's Mask... But that's only because I haven't gotten my hands on a copy of ALttP yet. I've seen a lot of praise for that game, and it seems like the model 2D Zelda.

Though, I may have one by tomorrow evening if all goes as planned...

Zelda II. The combat is a blast and I never felt more powerful than when I'm stabbing an Iron Knuckle in the face.

My favorite is still Wind Waker... why? Because it has a timeless charm, a great sense of adventure and exploration, some of the best designed dungeons in Zelda's history, and because it has been hated by many for all the worst reasons in the world...

My favourite Zelda, and probably my favourite game overall, is Majora's Mask. To me, it has a good amount of difficulty, great characters and side quests and the most interesting and original story of all the Zeldas. I also love the strategic elements you can put into the game to try and do as much as possible in the three days before the world ends, and if you have played it already you can plan what do, how long it would take and when you got to do it. A bit like Pikmin in some ways, which is also a game I really like.

Last time I played through Majora's Mask I specifically did as much as possible (and the Anju and Kafei quest for the first time) in the 3 days before summoning all 4 giants. I also beat all the bosses to make the lands peaceful and I believe I did all the Romani sidequest and one or two other minor things.

Tied between Ocarina of Time and Link's Awakening, I love those two ! Link's awakening was my first Zelda experience but OoT really got me hooked. Hmm

Link to the Past, because it's the first one I ever played and it to me has the most replay value (I've played through it over 30 times since it came out)