Roleplaying games vs Character

Many (computer) RPG's are pretty stupid regarding character choices.
Usually it boils down to making either a "Good" choice or an "Evil" choice, a splits "Evil" into "Egoistic" vs "Aggressive", but that is about the extent of 99% of player choice that impacts the game. And usually you are rewarded only for being 100% "Good" or 100% "Evil".

To me it would make a lot more sense to simply select a character alignment at the start and then the game sticks to it. Of course you could still have choice in dialogues, but these would then be more of a nuance of the character and would in general not influence the major conflicts in the game but only flavor your relations to individuals and situations.

To make it even more interresting I propose the following:
Have 4 main alignments (relation to others), one of which is choosen at character creation:

• Altruist - Totally selfless and will sacrifice a lot to help others
• Altruist with Egoist tendencies - Mostly helpfull but do look out for his/hers own interrests
• Egoist - Do not care for others, only for himself/herself
• Egoist with Sadist tendencies - Seeks to harm others, though not at great own expense.

Then have 4 subalignments (how the character comes to conclusions):

• Pragmatic - Considers the consequences of actions, do not abide rules and conventions.
  
• Emotional - Can act very differently to different situations, but have a hard time changing attitude.
  
• Idealist - Follows a set of ideals. There should be 2 different ideals for every primary alignment (out of 4-5), these should be interresting and display different choices in the context of the game world.
  

Now develop the 16 possible characters, and their motivations and build a game where one of these faces the same challenges and opportunities, and you will have a game with GREAT replayability.