I could go on forever about Disney since I've been there so much :blushing:, but I'll try and keep it brief.
It really depends on your budget, if you're on the dining plan and what you're looking for in a restaurant.
If you want character meals and buffets, I'd recommend Crystal Palace (for Pooh characters); Liberty Tree Tavern (for Minnie, Goofy, Pluto, although I thought I heard they may not have characters anymore either soon or recently). If however the food stays the same at Liberty Tree (e.g., ham, turkey, real mac & cheese etc.), it is very good. Cinderella's Castle is good, but as you found out difficult to get in. I believe you can make reservations as far as 90 days out and it used to be if you call 91 days out or even late morning on day 90th day, it might be sold out. Probably my new favorite though is the Cinderella Happily Ever After Dinner in the Grand Floridian. It has a wonderful variety of food and Cinderella, Prince Charming and the amusing stepsisters and stepmother are there.
For fancier dining, California Grill in the Contemporary, Coral Reef in Epcot and Boma in the Animal Kingdom Lodge are excellent. But if you like steak, Le Cellier in Canada in Epcot is THE BEST (although EXTREMELY difficult to get in).
For on the run meals, most of the Disney park restaurants are basically the same menu and price wise, although Pinocchio Village Haus and Pecos Bill in Magic Kingdom; Pizza Planet in Disney Studios; Electric Umbrella in Epcot and Restaurantosaurus (aka McDonalds) and Pizzafari in Animal Kingdom are usual lunch stops.
BTW here's a great site for
Disney menus with prices.
I hope that helps a little and have fun!!!!