Rainwaters, because of their... well, I wouldn't say rarity, but their lesser-known and lesser-bred status among the albinos. I know a lot of breeders that breed exclusively Trempers and lots that breed exclusively Bells, but not a lot that work exclusively with Rainwaters besides Hot Geckos.
I am head over heels for bell! I just love the cross with snows... That's my main project- Snow Bells... I just love that purplybrown color that they have in abundance and now and again you get a pinkish white eye with a red pupil- just beautiful!
I have all three, and intend to keep working with all three. Trempers can produce such rich colors and contrast, Bells lend themselves to bold striping and distinct patterns, and my Raining Redstripe is one of the most beautiful, colorfast geckos I have. She never looks dull or faded.