Lots of good advice.
If privacy is an issue, you want Aloha or Baja deck.
Carib is a little less private but a larger balcony.
The mini-suites on Dolphin are not private at all.
The mini suites on Emerald are private, but the location, all the way aft, may not be desirable to some--I happen to like them because most of my favorite spots are aft.
I agree with Hank though; a catagory BB on Caribe deck is the best bang for the buck.