If you are looking for something lowkey, not too fancy but still romantic with great food and atmosphere why not check one of these out:
Grand Floridian Cafe (GFR)
Il Mulino (Swan)
Olivia's (OKW)
Paddlefish (DS-L)
Terralina Crafted Italian (DS-L)
Trattoria al Forno (BWR)
Turf Club (SSR)
Wave (CR)
Wine Bar George (DS-L)
Wolfgang Puck Bar and Grill (DS-TC)
Why not sanaa or jiko at ak? Very romantic plus you can watch the animals after (night vision goggles) and look around the resort. Very cool, especially if your a little adventurous foodwise. It's definitely not food you can get in every town.
As Orangeanna mentioned above, my first choices would be Jiko or Sanaa. We've also done Olivia's and Turf Club and found them to be quite good. If you're in a bit more of a "party" mood, I'd suggest Raglan Road.
We are celebrating our 9th anniversary next week at Wine Bar George. It will be our first time dining there but I can't wait to check out the wine selection and try a few small pours.