I feel OoT is the superior game.
Ocarina of Time is a more epic
experience, arguably a more fulfilling title with respect to its size and story; it's definitely the pinnacle of traditional Zelda. But I don't think traditional Zelda is always the best Zelda. There's a lot of reasons why Majora's Mask is a better game; it's more challenging, has a fantastic core concept, ultimate a more rewarding and deep experience.
It's the only Zelda games where the side missions have as much weight as dungeons, and what you do between dungeons can actually be better than the dungeons themselves, which says a lot because I think all the four dungeons are a significant upgrade over any of the dungeons in Ocarina of Time.
It's got a lot of character, atmosphere and mood, and I think is all in all the smarter game; but for those who don't like change and prefer the same story retold with a slight twist I guess Ocarina of Time would be better. Oh plus it is pretty hard, it's really more of the thinking man's Zelda, whereas Ocarina of Time basically holds your hand the whole way through.
It set the groundwork for all subsequent Zelda games. MM owes it's existence to OoT.
...and Ocarina of Time owes its existence to A Link to the Past, which owes its existence to the NES Zeldas, which owe their existence to the hundreds of video games before it...
In other words, it's a totally moot point. While I give Ocarina of Time all the credit in the world for being a breakthrough game, Majora's Mask managed to improve the system.
I also gotta say, your so-called complaints about Majora's Mask are just stupid nitpicks. Why don't you lose key items? Well let's think about that for a moment; if you lost all your key items, you'd have to do everything all over again. Would you rather have that? You lose minor items because they're so ubiquitous.
As for the slowing time, since you only have to do it at the start of a cycle, it's really doesn't make a difference.You know what is annoying? Playing the Wind's Requiem EVERY TIME you want to change the direction of the wind in The Wind Waker. THAT'S annoying. Inverted Song of Time every couple of hours, not so annoying.
Tatl's got spunk, it's part of her character and it's amusing, also it furthers her character development, she starts out as a trouble maker who has to team up with Link out of desperation, but grows to become a valued friend and ally to Link. It gives the game a little more humanity.
Tingle in concept isn't a bad character, he's basically bizzaro Link if you take time to think about it, and since you're sort of in a weird, alternate dimension in Majora's Mask, it makes sense for there to be an anti-Link. Plus, he was very limited in his role in Majora's Mask to the point where I was just perplexed by his oddness.
Once again, you can look to the Wind Waker for throwing him in your face, making him a million times more annoying and integral, and well, just cementing him in the Zelda mythos.
And then there's the small fact that OoT is quite often brought up as the greatest game of all time - something I have yet to see MM be considered.
Actually if you read EGM's second listing of the top 100 games of all time Ocarina of Time ranked in at 8 and Majora's Mask at 7. Ocarina of Time is probably a more important game, but I don't really think it's a better note. More importantly, top games of all times lists are typically stupid and arbitrary and the result of a lot of internal politics of the organization that's compiling it. More often then not you'll see Super Mario Bros./Tetris/The Original Zelda as Number 1, Ocarina of Time has kinda lost its repute as of late.
That being said I think both Ocarina of Time and Majora's Mask are both brilliant titles that very easily complement each other and are my two favorite entries in the series. I used to be in the Ocarina of Time camp, but having only fully played through Majora's Mask last year, I found it's quickly become my favorite.