We have stayed at Port Orleans Riverside and at Port Orleans French Quarter as well as Caribbean Beach. We have not stayed at Coronado, mostly due to the room contianing only one sink and a office desk and chair.
Out of all of them, we loved French Quarter due to its compactness, only one bus stop and you get dropped on first if you share service with Riverside. The resort is small but it seems so quaint and quiet, just wonderful, everything is a short walk, plus you have boat service to Downtown Disney.
Also the rooms were recently renovated, oh and another plus, you can use all the ammenities and pool at Riverside, which I liek their pool better.