Thanks for replying guys.. interesting responses!
Independence_Day, that's a very cute story.

It's remarkable that initial repulsion *can* gradually change into "love" with time.... and understanding.
Which leads me to what TonyT said about
"if the dislike is based on misunderstanding and misinformation and two people learn much more about each other that is GOOD", this is exactly what happens in the romantic books and movies I speak of: if the two parties were TRULY disagreeable and had genuinely dislikable personalities, it would never blossom into love. The hatred is often based on presumptions and lack of understanding.. which are cleared up at the end when the hated romantic interest proves him/herself as actually someone with a good heart.
I suppose from the standpoint of creating a good story, with a 'happy ending', it's more satisfying to show a relationship that overcomes the perceived flaws of the other person and then falls in love, rather than the opposite (more common) route of falling head-over-heels first, only to grow apart because it was based on false ideals.
Honestly there are so many romantic stories (written by women) that follow this model: Anne and Gilbert from Anne of Green Gables, Elizabeth and Darcy from Pride & Prejudice, Margaret and Mr Thornton from North and South, Scarlett and Rhett from GWTW... these are just the ones that top the list. But it doesn't seem all too common in real life!