Pretty much Signatures only.
1.V&A
2.Il Mulino,AP,Jiko
3.Bistro
4.A possibilty The Wave may not be loud or full of kids running around.
We love kids,we love crowds but we also like time away at an adult restaurant with good food.And yes you can find that at Disney.
CG,FF,SAI,Chefs etc...have good food but the atmosphere is far from romantic.There is a great deal of bustle and noise that would preclude most folks idea of romantic.
CRT can be romantic under certain circumstances,we had a young gentleman propose to his fiance complete with the ring on a silk pillow provided by the staff.Everyone including the kids there got very quiet as he got on his knee and opened the ring box at the window seat just before the fireworks and we all cheered as they hugged.Not to many dry eyes that night.