i prefer ocarina mm gets to repetitive with the 3 day thing and the OoT has a much better story line i think
Majora Mask was an improvment in most areas but the 3 day timer was a pain in the ass.Constant rewinding of time makes bunnies cry.
OoT easily, I was dissappointed with Majora's Mask. It was a good game, no doubt, but OoT is legendary.
OoT is the more impressive of the two, becuase it was well first and included everthing that is expected from a zelda game (ie. Master Sword, Gannon/Gannondorf, and Zelda), but I find the the gameplay mechanics in MM much better.
Ocarina all the way... that game remains awesome, and the Master Quest version makes it 100000x more difficult.