1. Bad Buddy - it will take literally hundreds of posts for me to explain why this is the epitome of childhood connections to me, so I'll try to keep this short.
Their entire relationship was based on the fact that their parents hated each other. If their parents hadn't bothered to drive in the fact that they must hate the people next door, Pat and Pran could have been friends, yeah, but there's also the chance that they would've barely had a relationship. They went from hating each other, to not knowing why they had to hate each other, to pretending to hate each other while maintaining a friendship, developping crushes and finally dating.
I believe this is long enough as it is, so I'll stop here, but yup, one of my favourite childhood connection stories.