Im my opinion Port Orleans Riverside is the best of the moderates. I think it is the best themed of the moderate resorts and the grounds are beautiful. You really feel like you are in the Old South. I like the Mansions. Old Man Island has a nice pool with a water slide, and there is a big playground as well. Over on the Rumors and News board we have lots of discussions about things like Disney resorts. There are some pretty tough critics over there and most generally agree that POR (Dixie Landings as it used to be known) was Disney's best effort at a moderate resort as far as having an immersive theme. POR Riverside has some nice touches, including boat transportation to Downtown Disney, Horse and Carriage rides around the property, a good full service restaurant, and an extensive food court.
Of course you will find lots of other people with different favorite mod resorts - even in our house. My DW likes Coronado Springs best. For her, the newer the better and CS is the newest of the mods. The grounds are very nice, as is the pool with slide. There is also a nice playground for the kids. Pepper Market is an upscale food court with very good food. Since CS caters to Disney conventions there are a few more amenities, such as up scale full service restaurant and bars.
Good luck deciding.