As everyone knows Andie tragically ended up with Blane (Andrew McCarthy) in the actual finished version of the film. Here's a taste of what could have been, taken from the last few pages of the book:
"Duckie was back by then. Andie took his hand and walked him out to the dance floor. The crowd separated around them again, leaving Andie and Duckie alone at the center of the floor. She took Duckie in her arms. The orchestra began to play again. Duckie grinned. And then his face froze with terror. "Andie" he whsipered "I can't dance"...
...Blane wasn't grinning. He was smiling. And so were Andie Walsh and Duckie Dale. They held each other as the couples around them began to dance again. They held each other and smiled. They danced around and around, smiling at each other, then laughing, dancing around and around and around, until they were one - one whirling, smiling, laughing blur of pink.
(Note - OMD recorded the song Goddess of Love to go with this ending, which was changed to If You Leave to suit the new ending)