Magical Express worked well for us. If you really won't be using a car once you are on Disney property, it's a no-brainer. The bus ride was clean, comfortable and quiet. Also very efficient (although they did make us catch an EARLY bus on the return; plenty of padded time). I would use it again if I were staying solely on Disney property.

And just a quick ps to the Contemporary suggestions....I personally prefer the Wilderness Lodge (though not on the monorail, they do have a boat that will take you to the Magic Kingdom) and also prefer the Polynesian. Both of those usually run about the same price per night as the Contemporary.