I always say Majora's Mask. I enjoyed the side quests that focused on helping others with their issues in life. I also really love how you use time travel to your advantage. You don't keep your items or most of the accomplishments you've made, but the advantage you get from doing tasks before going back is the knowledge that allows you to bypass tasks you had done earlier. I find these puzzles fascinating.
Runner ups are OoT, and ALttP. OoT really has little to no major faults that turn people away from the game. It's a good starting game for new Zelda fans as it explains the basic Ganon/Zelda/Link plot. The game also introduced features that have been a part of every 3D zelda game since such as lock on, multiple item mapping, and the action button. ALttP introduced the modern dungeon design, and was incredibly difficult to the point that you almost needed to do side quests just to get upgrades. Otherwise, the difficulty would spike to near impossible in the second half.
Common favorites that aren't mine, TP and WW. TP was an awesome collection of references to past Zelda games and was a real beauty, but combat was too easy throughout. I don't believe I died once except from the miniboss in the yeti mansion. I hate WW's ocean. I baisly hate it. I found it monotonous and boring, and Triforce hunting made me quit the game for several months. >___> Pretty good game otherwise.
EDIT: I forgot about Four Swords! While the game didn't really offer anything new and was mostly 4 player aLttP without an explorable overworld, the game IS incredibly fun with a bunch of friends. For that reason, I have a lot of memories associated with Four Swords (not Minish Cap though). I wish the voting poll didn't group the games together because I would have been split between MM and FSA.
