The Grand Floridia is very romantic and nice. We never stayed there but it looks really nice. We've stayed at the Contemporary and the Polynesian. They too are very nice but along with the Grand Floridan are very expensive. My favorite of the Magic Kingdom resorts is the Polynesian mainly because it is close to the transportation and ticket center where you get the other momorail for Epcot.
Just some advice, you do have to make some reservations months in advance. You may want to invest Birmbaums Guide. This book can be bought at ant Disney store and is very good. It gives a lot of great advice planning the trip and is also good to carry with you while there. Tha's what we do.
Keep us posted on what you pick. Email me if you have any questions.
Tom