One thing I'd like to talk about with respect to Majora's Mask is the overworld and dungeon design, how they link, and why Majora's Mask has the best overworld of any 3D Zelda and the highest quality dungeons, even if there are only 4 of them.
In Ocarina of Time and Twilight Princess, large parts of dungeons are simply trivial. There's the first part of the dungeon, which introduces you to the central mechanic - the spinning centre of the Lakebed Temple in Twilight Princess, or the dimension-twisting passages the Forest Temple in Ocarina of Time. This central mechanic is introduced at first in a very easy situation, and then it gets steadily more and more complex as you progress. Eventually, you reach the miniboss, and obtain a new item. You are then exposed to challenges which test your ability to use the new item, again starting at very easy and progressing to harder. At the point you fully master them, you get to fight the boss, who normally uses the new item you acquired in some form.
This means dungeons have a weird pacing issue - the bit just before the middle is hard and the bit just before the end is hard, but they always have a lull where the new item is introduced. The second consequence of this is a spill-over consequence: new items are tested to completion within dungeons, so there's not really any point in using them in the overworld once you get out of said dungeon. The amount of times you use Twilight Princess's Spinner, for example, despite it being a really fun and interesting item, is essentially minimal outside of the Arbiter's Grounds, the dungeon it gets introduced in. After all, you know how to use the Spinner now, so introductory puzzles would be almost insulting, and complex puzzles would be wasted when they could have gone in the dungeon that is meant to be the critical test of your skills. Overworlds have a tendency to be dull and empty in both games because it isn't really apparent what they're for: any tests of your ability are reserved for dungeons.
Majora's Mask only has 4 dungeons, but it only has 4 dungeons for a reason: almost all the important items are actually given to you outside dungeons. In fact, if you look at the items given to you in dungeons, you have: the Bow, the Fire Bow, the Ice Bow and the Light Arrow; which are really just extensions of the same basic item. In Majora's Mask, the game presents you with items and transformations (which effectively are items) outside dungeons, actually in the overworld itself. You can turn into a Goron long before you enter Snowhead; you can turn into a Zora long before you enter the Great Bay Temple. More than that, the 'basic tests' of these items are established in the overworld. In order to get to Snowhead, you have to have figured out how to competently use all of the facets of the Goron transformation already. At no point in Snowhead is time wasted on a series of basic tester rooms that get you accustomed; it's simply assumed you know how to do it - and you do, because otherwise you wouldn't be there. It's the same for the other dungeons. You can't get into the Great Bay Temple without being able to use the Zora transformation really well - or you wouldn't have managed to beat the Beaver Brothers. You can't get into Woodfall without being good enough with the Deku Mask to transverse the swamp.
This has two big advantages. The first is that it makes Majora's Mask's overworld really engaging. It probably has the most genuine, non-filler content in the overworld of any Zelda game. Figuring out how to get into Snowhead, managing to navigate through the Deku swamps, figuring out the puzzles of the Ikana canyon: these are really fun and really good ways to get you accustomed to item use without even noticing you are. The real benefit, though, is that it means dungeons are hard. Majora's Mask doesn't pussyfoot around. There are basically no tester-rooms. The puzzles are complex and immediate. Because of this, the dungeons are genuinely engaging and display a level of design that the rest of the series often just dreams of - particularly looking at Wind Waker's rather bland room sequences. Woodfall Temple is probably the most satisfying initial dungeon in any Zelda game, Snowhead has a genuinely incredible interwoven design around the central pillar, the Great Bay Temple is the best water dungeon in Zelda bar none and figuring out the current puzzles is actually quite challenging, and Stone Bay Temple is just the outright best dungeon full stop in Zelda bar none: it is masterfully designed; and really pushes your limits as you try to figure out the multi-dimensionality of the dungeon.
The fact there are only four dungeons is really immaterial: there are four because the overworld is actually taking up the slack in a way it doesn't in other Zelda titles, and as a consequence Majora's Mask can have some of the best dungeons in any Zelda title.