Hi there,
Congrats on going to WDW, you'll have a blast (though that is the BUSIEST time of the yr to go, get out early early and take a break mid day.)
I have stayed at the Contemporary 6 times and the GF once (4 of the Contemp times there was no GF).
Let me preface what I am about to say with this; the Contemporary is a very cool resort. It is fun (especialy in the tower) and I think the concorse steak house blows any restaurant in GF away.
Now let me say this;
The GF is the best darn resort out there. The place is very pretty and has all the other amenities (such as marina, monorail, and room service)
I think the Contemporary has quite a bit of sentamental value to most of its die hard fans. Back in the day it was the tops of the WDW resorts.
p.s.
Having just been down to WDW in May, let me share one tip with you that is a bit off subj.:
Get a rental car, nothing fancy, we did a week for about $140.
It was so worth it that we said that even the next time we stay at a monorail resort (we were at CBR this time) that we would want the car for getting to Disney Studios, DTD, other resorts, or mini golf.
It makes it soooo much nicer to have the mobility and freedom to get in and out of non-monorail sites at our leisure.
Have fun, and definatly go with the GF (but be prepared for some fussy menus at their restaruants {I like upscale dining, but there was literaly nothing that sounded all that good at GFs restaurants, but I also thought that about Contemps place on the top of the tower, the California Grill...just too fussy}