FF without a doubt. We *liked* Artist Point. Everything was good. Service was attentive, if maybe a tad pretentious? It's a nice place, but the decor doesn't feel special to me. It feels kind of hotel-ish.
Flying Fish on the other hand feels special. It's an upscale restaurant, but it feels very un-pretentious, more fun, more bustling. The service is excellent. It always seems like it takes awhile to get drinks, though.

The waiter we have had (yep, same guy 2 years in a row) is very knowledgeable and friendly. The menu feels a bit more progressive than Artist Point. It is one of our favorite WDW restaurants.
Two quibbles with FF: (1) the afore-mentioned slow drinks - don't know why, but it happened both times; (2) cold dessert that should have been hot -the waiter was APPALLED when we told him. Those things notwithstanding, it is on our list for our 2010 January trip.
If AP works in your plans better, I don't think you'll be disappointed. The food there is VERY good. It's just not a very special experience.
BTW - I prefer the ambience at FF to the Cali Grill, Jiko and Brown Derby as well. We've never tried Narcoossee's or Citrico's so I can't comment on those (next trip - maybe!), but of the signature restaurants we've experienced, the atmosphere at FF is the most enjoyable and easy-going.