The Beast even let go of his hopes to be human again and allowed Belle to return to her father, perhaps for ever. (He didn't know she'd come back.)

The dude wasn't even in the human species...
Second one goes to Cinderella and Prince Charming. Yes they did have lust, but if you watch the other movies you'd see how big their love REALLY is. And there's no doubt it's bigger than Aladdin and Jasmine's.
Third goes to Mulan and Shang which at heir time honor was a big thing and still is in my family so I know how hard it was for them. Plus they were together mostly as boys so...
Fourth would be Rapunzel and Flynn. He risked his life to save her. However P.C and Cindy, Mulan and Shang bet this couple because they also risked their lives but more critically. Rapunzel even risked the death of her mother. And I have nothing against that.

Also, Jasmine & Aladdin :)

I wanted to go with Eric and Ariel that are and will always be my favourite Disney couple, but Rapunzel and Flynn can hardly be beaten when it comes to representing "the truest" love because Flynn was the only Disney "prince" who literaly died for his princess and Rapunzel, after facing the world and falling in love with it for the first time ever, was ready to give up on all of it and spend her entire life in isolation just to save him.

Because the other's I can see going with other people. Snow and her prince, I can't imagine them being with anyone else.

Really? Belle/Beast is top? Whatever.