Hi Alexia! This is certainly not an easy question to answer since all three are outstanding Disney resorts. One of the best ways for you to come to a decision is to compare them side by side at the Disney site. Please click
HERE to get to this page.
All three will offer similar amenities. The Grand Floridian is considered by many the deluxe of the deluxe at Disney. It is beautiful but I find it a bit stuffy in atmosphere. I like something a tad bit more laid back. It does have the best spa on property just a few steps from its door if that is something you would find useful.
The Polynesian is the ideal spot for those that want to have that relaxed feel. It will make you seem like you stepped right into the islands with the grand open lobby and the extensive landscaped grounds and pool area. This is a very popular resort for families and honeymooners.
The Contemporary is often the hidden secret. The best rooms are located in the main building and you can have either a Magic Kingdom view of a Bay Lake view which happens to be just as beautiful especially at night. The rooms are a bit larger then other resorts too.
Since they are all located conveniently on the monorail system the decision comes down to what theme you and your family would enjoy most. They will all offer you some of the same Disney magic with their own flair of atmosphere!