Preferred rooms costing extra nightly are in Trinidad North and Martinique. If you want to be very close to the main pool and food court these would be the best locations. I think they are worth the money.
If you don't want to pay extra many like to request Jamaica or Aruba. They are a short walk across the bridge on the other side of the lake.
You might want to read the CBR FAQ threads listed below. It contains a lot of great information. I also have lots of CBR pictures. You will love it there.