Thinking about ways to replace the 'alignment' types from old D&D with something more sensible but still clear and workable for mechanical roleplay... that is, something that makes sense in a computer game, and allows you to see the personality 'stats' of your character and adjust them through choices. If your choices have meaning within a CRPG it is often useful to the player to have stats for them. Sure, it's not completely realistic, but neither is knowing that you have 17 of 21 hit points remaining.
I was reminded of the old nature-and-demeanor system from White Wolf, mostly becuase the phrase 'Bon Vivant' kept popping into my head while thinking about my current BG character and her romance with Coran, and also of the dragon age voice system. So... how about a personality wheel, then? Something with far more options than the three from DA, enough options to cover NPCs, maybe 9 to go along with the alignment feel, maybe not.
You choose a personality type when designing your character. As you play, in dialog, you get response options which correspond with your personality type and the neighboring types. If you consistently choose options other than 'your' option, your personality type slides over to a new setting. You can also have occasional special options available only for your current type, and other characters will react to you based on your current type.
This also means you can have your personality adjusted by magic and have all your dialog options automatically shift to reflect that you're now a Gloomy Gus instead of a Valiant Hero.
Problem: This means every player-respondable line of dialog requires A ZILLION OPTIONS.