Clarification: I have played and immensely enjoyed both but I can only download one on my Wii and I can't decide.
Ocarina is better as a more 'classical' adventure, Majora is just....crazy, but in a cool way. I recommend both.
I like Majora's Mask A little more then OoT, MM had a unique gameplay to it.
I consider Ocarina of Time to be better (I actually consider it the finest game ever made), but only just. Majora's Mask is an incredibly well-written and well-designed game like Ocarina of Time, and the repeating 3-days mechanic is brilliantly implemented. I'd get Ocarina of Time first, but then get Majora's Mask as soon as you're able. Both are timeless classics that everyone should experience.
The N64 version of OoT is better, the Fire Temple music was changed in future lawsuits do to an Islamic group finding http://www.youtube.com/watch?v=e056R97svz8 offensive in the game. It was changed to a FAR less creepy song.
Actually even most later N64 versions of the game had the changed FIre Temple song. Which is unfortunate because that song is amazing.
Actually all OoT music is great.
Actually all Zelda music is great.
I preferred OoT, and still play through it once a year. If you can (I don't what the Wii Store offers), see if you can get the Master Quest bundled in. It just adds different dungeon layouts, but that means a second play through can be worth it to see the new layouts.
Sadly, I don't own an N64 anymore, but fortunately, I own a copy of OoT with the original Fire Temple song.
Ocarina of Time no doubt.
I hated Majora's mask, couldn't could into it.
Well I have it on my Ipod, so... haha
Both games have astounding OST's though. Forest Temple song still gives me chills.
I thought majoras mask was the worst zelda game ive ever played in my life, and i discount it among the franchise when talking about zelda (i see it more as a side game, like some of the gameboy zeldas. I mean it literally came out like a year after ocarina of time, and zelda games always have like 4-5 years between games). Ocarina of time was one of my favourite zelda games as a kid (though a link to the past is the better overall game in my personal opinion, but maybe it was because i played it a lot before ocarina of time came out).
Though overall, i like twilight princess better then Ocarina of time when it comes to the 3d zeldas. I actually really liked Windwaker as well, even though im not a fan of the cell shading style they went for in that game, the gameplay was great.
Still, if it was my decision then ocarina of time hands down, just because i hate majoras mask so much.
I liked both, but I think OoT gets a little too much praise IMO. I would go with Majora's Mask if I had to choose.