We just got back from a trip in December. We ate at all four!
Between Tony's and the Castle, I'd pick the Castle. For the Tony's is expensive for dinner, almost as much as for what you'd pay at CRT anyway. But both have very good food!
As for Poly and CR, we ate at Kona's and thought the food was FANTASTIC!!! The best kept secret of WDW, IMO. We didn't eat at Ohana's, but it gets great reviews too, especially if you're a big meat eater. I loved the CA Grill, we got a window seat durring Wishes, which helped.
Of the four, Kona's is the least expensive, if $$$ is a concern.
Really, you can't go wrong with any of the choices! So don't worry to much about it!