I cry like a blubbering idiot! Belle loved the Beast for who he was on the inside. This sets a high standard for all of us.
Psychologically speaking, you can also argue that Belle loved the Beast for the man she was able to shape him into becoming. He was uncouth, uncivil, unsocial to the point of being sociopathic, but she "worked" with him, and made him someone she COULD fall in love with, the perfect gentleman slash warrior. Someone who could kick anybody's a$$ but still sensitive and gentle & loving.
And then he became, like, totally hot.
Not trying to psychoanalyze anyone on the boards honest, but I've seen plenty of women in my life date, live with and marry men who were total tools, and they made it their life mission to "change" him. And I'm sure most of us know at least one woman in a similar boat, trying to mold a guy who doesn't want to be molded into a gentleman he doesn't want to be, to the point of ignoring obvious character flaws. Putting up with months of Nasty for the occasional night of Nice. The couple that makes you ask "Doesn't she know that she can do better?"
While BatB has fun characters, zippy songs & exciting action sequences, it is the ultimate "I can change him" fantasy. The main difference between its story and most contemporary scenarios is that Belle wasn't necessarily looking to fall in love with the Beast. Mainly, she saw herself as being stuck with this SOB, perhaps for the rest of her life, and while she couldn't escape, she had enough inner strength to not be willing to put up with his crap eternally. She had to change him in order to make a situation she was forced to live with, better. But once she "civilized" him, (or, if you prefer, changed him back into the wonderful person he USED to be before he became such a hard-a$$, and isn't every hard-a$$ a perfect gentleman deep inside once you teach him to remember to be a perfect gentleman?) oh, what a wonderful man to have around the house.