I haven't been to V&A but I would guess that would be the most romantic.
However, of the other signature locations, I would pick in this order:
1. Citricos
2. Artist Point
3. CA Grill
4. Jiko
I think the decor in Citricos is classy, the food is good, and I didn't think it was loud at all. Artist Point the decor is simple, but if you can get a table at one of the windows, the view of the lake is nice. CA Grill can be loud, especially if you go near fireworks time and it is really crowded with the bar etc, but the view is great.
Jiko is also nice and has interesting decor and good food. However, I didn't care much for the view of people going to/from the pool (shirtless) or wrapped up in towels. It also go loud in there too from the people in the waiting area for Jiko/Boma. We were seated near the front of the restaurant so it might not be as bad toward the back.