I find Wind Waker to be the easiest game in the series... that doesn't mean that it's bad. I love Wind Waker. It's an enchanting world to be in (I'm speaking from GameCube version, I haven' played the HD as I don't have a Wii U and, frankly, I'm a little afraid to say this, but I've been kind of *against* the whole concept of an HD remake because I'm in love with GC's "flat" art style for it). It, however, is very easy as far as general gameplay goes.
Skyward Sword kind of ties with it / rivals it, in that it has a lot of hand-holding. I found that it had some challenge in regards to the motion control sword-moves (I thought it was neato-burrito that certain enemies needed a certain finesse...), but Fi's uber info-dumping and other hint-systems in the games really made it... one that would make a beginning player not only take it easily, but also yelp at Fi to shut up already.