I have very few rules, but the ones I have cover everything. Too many rules is too much to remember for both kids AND adults. I go with the KISS (keep it short & simple) philosophy: respect, responsibility and manners.
1. Respect - for yourself and others, for your things and the things belonging to others.
2. Responsibilty - for your words, deeds, and actions, for the things you are asked to do, for your own space not only at home, but in life in general.
3. Manners - Ma'am/Sir, please, thank-you, you're welcome, holding doors if you get there first, and simple common courtesy & politeness is NOT AN OPTION - it is a requirement in my house.
But, if you really think about it, with these 3 simple rules, what have I missed in how we all wish our kids would behave and grow up?