Who was it who said that neighbors would be wonderful, if they just didn't live so close? Perhaps someone who had lived across the street from an unusually noisy household, next door to someone who refused to trim a heavy branch that looked like it would come down in every storm, or down the street from a barking dog.
Neighbor issues are particularly thorny because by definition, you're going to be dealing with these people again. You're going to see them on the street and probably run into them at the grocery store or your kids' soccer matches, and you don't want to ruin whatever relationship you have. So when trouble is brewing, take a breath before deciding to enforce your legal rights to the absolute maximum. Always learn about the law and then start with a conversation, even if you're doubtful it will help.
In some circumstances, another good avenue for neighbors can be mediation--a session with a trained, neutral third party who can try to help you arrive at a good solution. Many cities now offer free or low-cost mediation services for neighborhood disputes.