Ok, here are my comments, short & sweet...
California Grill - good food, but too noisy
Les Chefs de France - Very elegant and quiet. Be forewarned that most of the waiters have VERY thick accents.
Jiko - Very nice, especially if seated by the water. Go walk and look at the animals afterward.
Artist Point - They usually serve more exoctic food, like ostrich or wild boar. It is very good, but go later in the night when less kids are around. If you are just a couple, you have a better chance of sitting by the windows. After you're done, walk by the waterfall or down to the beach.
Rose n Crown Pub - If your idea of romance is sharing a pint together, this would be great. Make reservations later in the night and you can finish up dinner while having lagoon-side seats.
Sci-Fi Diner - If you want to pretend you're teenagers again at the Drive-In. Just watch out who you share a car with.
Hollywood Brown Derby - If you can get a booth, yes. Otherwise, the tables seem to be very close together.
San Angel Inn - The concept is very cool, but the tables are very close together. Sitting close to the river is nice, but the people passing by in the boats seem to always want to take pictures of the restaurant, blinding you in the process.
L' Originale Alfredo di Roma Ristorante - I am drooling at the thought of their alfredo! Sometimes they will have strolling musicians, which can be nice.
Restaurant Marrakesh - Belly dancing anyone? The dancer will also invite others to dance with her. The food is very good, and they give you A LOT!