Can I only pick one?! O'hana, definitely. We've eaten here at least 5 times over the last 10 years and it was barely recognizable as the place we used to enjoy when we ate there just a few weeks ago. Barely any entertainment, rushed, impersonal service and a ton of meat just plopped on plate without asking what I wanted or how much. It was really terrible - no coconut races, no limbo, nada.
Cali Grill - the food just isn't up to par with some of the other signatures on property. Too much rice in the sushi rolls and my scallops were so spicy I could barely eat them. The view barely made up for the lackluster food.
It's ok, though. There are so many underrated gems in WDW, IMHO, so the good tends to make up for the bad, IMHO.