If we're going with D&D alignment, you know back when that still existed, I'd have to say I'm either true neutral or chaotic neutral. I don't go to extremes, I have my own rules that I mostly follow, but they're not always the same as everyone else, and I bend them when it suits me.
For something more like Fallout karma, I'd probably be neutral by virtue of doing relatively equal amounts of minor good and minor evil, while mostly staying out of the big things. Occasionally I'll do some moderate good, but I rarely go further than minor evil. Not because I have some moral objection to being a bastard, but because the consequences of doing so are almost always more trouble than they're worth. It is karma, after all. You reap what you sow.