Without a doubt, our favorite has been CSR. Obviously, it's the most fresh in our minds, but I honestly can't say anything bad about the resort.
Our stay @ POR in 2008 was nice, as it's was our first trip as a family and our first time staying on property. We were there as part of a grand gathering with my family (14 of us total). Had a really nice time there, enjoyed the boat to Downtown Disney, and our location was good (we were in the "mansion" type buildings). I will say I thought it was somewhat difficult to maneuver through the resort and I wasn't crazy about sharing buses with POFQ as it made the stops take longer and the buses were almost always crowded.
Our stay @ CBR in 2010 was also nice... the theming was very "vacation-y" feeling to us. We were in Barbados, Bldg. 16 (I think). It was 2 villages from the main area, but again, the buses took forever to run, as they had to go to 4 other stops before leaving for the parks. There wasn't a bad reason we didn't want to return to CBR in 2011... more that we just wanted to try something new.
Now, our stay in Sept. @ CSR was truly wonderful! I know that a lot of folks mention how big CSR is, but we didn't see it as being any bigger than POR or CBR. The queen beds @ CSR are a huge plus for my DH and I, as I'm 5'11" and DH is 6'1". They were super comfy, and us sharing a full sized bed @ POR and CBR was just not very conducive to getting a good night sleep and was also somewhat laughable!

We both slept wonderfully at CSR. I loved the divider doors between the sleeping and bathroom areas. It definitely allowed me to get ready in the mornings without waking the girls before they needed to get up, whereas POR and CBR have curtains you can draw. Good for privacy, but not so good for keeping the hair dryer noise level down like you can with the divider doors. We didn't miss having a table and 2 chairs @ CSR... and I loved the air conditioning situation @ CSR too. It wasn't the noisy wall units like you have at most other resorts.
We aren't headed back until 2013 probably

, but we've already discussed it and plan on making this our new "home" at the World. We really enjoy the spread out layout of the moderates, and we love how quiet the Ranchos section in particular seemed. I admit that years ago CSR was the resort that I least wanted to look at (in the way of moderates) because of the convention aspect, but we found that in a way, maybe having a convention going on was a good thing, as it seemed to keep the # of bus riders down. There was a convention going on while we were there, but it didn't affect us negatively in the least.
~Kelly