I have used
Dreams Unlimited in the past, but have lately been using Dream Come True Vacations - Joe and his team search for the best deals for me, make Priority Seatings (even got us Cindy's breakfast!) - saved us $390 by automatically applying a code for one trip. They respond very quickly to my emails.
All that being said, you asked for "GREAT Disney Deals"... as you may have noticed, all that has been available for this year has mostly been PIN codes, FL resident rates, and AP rates.
For my upcoming trip in June, I started by booking with a
AAA rate, but then once I told Joe that we will also be going back in December, we did the math and decided that an AP was the best way to go for this years trips.
I have found that all of the best Disney-specialist agencies ALL know how to get you the best rates - the rest comes down to how happy you are with their customer service.
I guess what I am saying, is that I don't expect you to find any one of these agencies finding you something "GREAT" over the others.