If you are looking at the square footage they are as follows:
Explorer of the Seas - Junior Suite 277 balcony 69
NCL GEM - Mini Suite 231 balcony 54
CCL Pride- Junior Suite 275 balcony 40
Since this is a special anniversary (congratulations) if you can swing it you might want to look at the NCL Gem and "The Haven" cabins. You would have many added amenities with your own private pool courtyard area.