Gud

While most of the others are more "traditionally" romantic ones I can't Think of a more romantic moment (for me) that this one.
Beast had given up hope and was willing to let Gaston kill him and Belle's return made him want to live again and it showed that Belle truly loved him even if she didn't know it.
This scene is (maybe a bit too obvious) a reference to "If you love something let it go" saying and I love that.

Or the death of Beast and Beast lets Belle go.

Dancing scene and I also love the sweet little moment they share on the balcony reaching for each other's hands.

More on his part than hers, but still.. so romantic. Gah

I loved how they really seemed to bond during this scene. It's really sweet.

it wrecks my heart, swells it up, makes me believe in the true love. I break out in tears everytime i see this