To me, the most overrated is Ocarina of Time. Yes, it’s an important stepping stone for gaming, but I feel it doesn’t really stand the test of time. Many other Zelda games have done things it has just much more effectively, and it’s especially evident how vanilla OoT is nowadays when you compare it to its immediate successor, which is by far a more interesting gaming experience even today.
Most underrated is either Twilight Princess or Skyward Sword, though for different reasons. Twilight Sword gets overlooked a lot but I feel it takes all the best aspects from Link to the Past and Ocarina of Time and just makes them work so well. I love the style and the tone and I don’t even care if a lot of the items are just used for one dungeon, the dungeons themselves were still very engaging. Now, Skyward Sword May not be my favorite, but I really don’t feel it deserves its reputation as the franchise black sheep. Yes, it’s much more confined than the other games, but that doesn’t immediately make it bad. It’s gorgeous, it’s got a very interesting story, and some of my favorite dungeons in the series (the Great Cistern is still the most fun I’ve ever had in a Zelda dungeon). And while we’re at it, yes I feel the motion controls actually added to the experience.