Not quite an "alternative" but something different I did in a game once was make alignment more important.
Instead of Gods, the campaign world had "forces" of law, chaos, balance, good, and evil, that were as potent and real as anthropomorphic deities.
Each "force" had a set of 3 values, such as good=truth,love,courage; evil=doubt,contempt,self. Balance took all the values and combined them, such as truth+doubt=skepticism, love+contempt=compromise.
good and evil didn't play as black and white concepts, because the core of the ethics system allowed that "evil" could be productive and necessary. Unchecked Love, for instance, would lead to Martyrdom, just as unchecked Contempt would lead to Hatred. The concept of Balance (neutrality in alignment terms) was very important to the world.
When the players were into it, it worked out very well. The character core ended up being more about ethics than morals, which I think is a concept close enough to the "alternative" system you're discussing.
The idea for this came from Ultima 7 part 2 (the computer game), and I lifted the law, chaos, and balance stuff straight from there. It was the game that put a different twist on the standard Ultima virtues.
I've got the whole system written up if anyone's interested.