I loved the side quest in MM for the couples mask (Anju and Kafei), it was probably the most in depth side quest in any of the Zelda games. While some may have had more trades or actual components to it, the couples mask side quest factored in time which was a big deal. Not only did you have to do a lot of trades, but you had to do things at certain times of it would fail and many other parts of the game needed to be completed before attemping this one. There were side quests in MM that were made specifically to lead you into the couples mask side quest.