Alignment is a great descriptive tool, but as anything else, it fails miserably.
The days of "but that's what my character would do," alignment restricted classes, Helm of Opposite Alignment (or whatever the hell it was called,) failing paladins, and all the other associated garbage that came with it should be swept up and incinerated.
Where I will always use alignment, is as shorthand notations for monsters, NPCs, and organizations in my own notes, but I will continue to attach more descriptive details as they become relevant.