Everyone has their favorites! What seems great for one is disliked by another. I don't find any of the Disney table service restaurants bad. Just some better than others.
Our must do's every trip are Ohana, Coral Reef, San Angel, The Wave, Kona Cafe and Boma. Ohana is the most difficult to get.
Be Our guest for breakfast or lunch is excellent, especially the atmosphere. Dinner is good as well. But it is VERY popular and hard to get.
For quick service, Sunshine Seasons (Epcot), Tangerine Cafe (Epcot), Flame Tree BBQ (Animal Kingdom), Wolfgang Puck Express (Disney Springs)
Our next trip we're trying a few new ones recommended including Yak & Yeti (Animal Kingdom)
We skip Rainforest Cafe as we have one local. While it is good I prefer restaurants that are unique to Disney. However, if you have kids they might enjoy Rainforest.
Since your are heading there in September you may find it difficult to get a reservation for the more popular restaurants as many already booked. So book yours ASAP!!