Personally, I don't think there is a "best" dinner rotation. You end up with all of the same menus over the course of your cruise, no matter what rotation you are on.
Some people like to choose their rotation so they can be in Lumiere's on Formal Night. On our last cruise we were in Parrot Cay on Formal Night and had a blast. It was no less fun because we were in a tropical-themed restaurant. And we were in ANimator's Palette on Tropical night and had fun, even though it wasn't a tropical-themed restaurant.
There are so many details involved in planning a great cruise but, IMO, rotation selection isn't something to worry about.