Orandas and ryukins can be awfully fun when they grow to their proper sizes. They actually can get 10" or larger when given the room and a good varied diet. And they're so much more... bumbling than the torpedo shaped varieties. Very friendly, personable fish. They're easier to interact with because they aren't as hyper as comets.
Although they are prone to a few more health problems, and they are much more delicate, requiring sinking food, the occasional feeding of peas, and special consideration as far as tank decoration, current, etc. Not quite as low maintenance as the hardier varietes. But darling nonetheless.