I think Sen & Nussbaum have it spot on in her capabilities approach to ethics (although I think it needs to be slightly revised to include some other animals too).
In a nutshell, they outline 10 categories of conditions necessary to allow a human being to flourish (essentially to grant a human being the opportunity to forge a satisfying life).
So for example some of the principles are bodily integrity, freedom from emotional abuse, permission to own modest property, permission to participate in social institutions, permission to engage in meaningful relationships with other humans, animals and plants, permission to recreate (and it goes on - I can't quite remember them all - you can wiki it if interested).
So they've listed a number of things they feel necessary for a person to have the opportunity to live a happy life, regardless of race, culture, era or location.
Moral deliberations then simply become a matter of deciding whether an action facilitates or inhibits any of these conditions. If you inhibit these conditions, you act immorally. If you facilitate them, you act morally.
I don't think it's a perfect model, but I do believe it's the best one I've ever learned about, because it is objective and very practical (unlike other moral theories which are always ambiguous in some ways).