I am a huge advocate of
Dreams Unlimited, one of the sponsors of this site. (And no, I do not work for DU, nor do I personally know anyone who works for DU!)
I am also a AAA and Disney VISA card holder, but I have vowed to never do Disney again without DU! DU will look for discounts for you, although admittedly, I don't think they can book AAA rates anymore. However, I have been lucky in finding discounts much greater than AAA. DU will look for codes that apply to your ressie, and you can also let them know if you get a code sent to you. Often times, I get a code e-mailed to me, and I e-mail my agent, and they have never failed to get me the discount.
Additionally, they provide wonderful service, at a level you are comfortable with. I really enjoy planning, but making the phone calls can be difficult because of time differences, and also frustration with the CRO agents at times. This way, I can still do the planning, but they do the booking. They will also book dining for you, which is an awesome service.
I believe you can't go wrong with DU -- you won't pay anymore with them than if you booked thru Disney directly, and at least this way, sponsors of this site will be benefiting from the commission. I haven't had stellar experiences with the AAA agents in my area, but I have always received great service (and rates) from DU.