For me its French Quarter or nothing. I wasn't a fan of Coronado when we stayed there. The pool is nice, but it was pretty spread out. The whole desert motif really didn't do it for me. Haven't been back to CBR in a long time. It just felt really "old" and not that well maintained, but I don't remember any other major complaints.
I have never stayed at Riverside, but I have walked or jogged there on the many occasions we went to FQ. I will say it is very lush, and it is kinda fun to walk around. But I didn't think the feature pool was very impressive (it does have a better slide than FQ however) and with the river going through the middle of it, it seems like it takes a long time to get to places.
FQ is my pick. I like the compact nature of the resort, and how easy it is to get to the pool and food court. I really enjoy the feature pool, and the way it winds around providing a lot of seating areas. I really like the design with all of the mardi gras props and the general look of the buildings. This hotel says I'm on vacation, Riverside feels like I'm in a remake of "Gone with the Wind". But I think that part of it comes down to personal preference.