Big problem with alignment is that it means different things to different people. the best thing you can do is talk to your group about what alignments mean to them (not 'which is the best alignment' but what each alignment represents) and work from that.
My 10c worth on the 'good' alignments:
Lawful Good: You believe that a society with codified laws serves the people. You believe that such laws represent true Justice. If a person or society doesn't uphold the Law and behave in a Just manner, they must be deposed, arrested, tried and punished according to the Law. If the Laws do not serve the people they protect, then they must be changed, legally, so they do so. Duty and Honor must always be observed in any action you undertake.
Neutral Good: What is the most efficient and convenient solution to this problem? Evil exists and it must be fought. It doesn't matter how, just as long as it's done quickly to minimize the damage. The point to life is giving, lifting everyone around you up to a higher state of being. Charity is the gift of life. Laws should serve the people, but often they don't. Unjust laws should be ignored or abolished. Spontinaity is also good in moderation, too much chaos breeds evil, however.
Chaotic Good: Laws don't serve the people, they serve the people in power. Law inhibits the ability to do good by placing restrictions on when, how and where doing the right thing is appropriate. Doing the right thing should always be appropriate, no matter the circumstance. Of course, one must be intelligent and cunning in promoting good because evil is insidious. Evil can use and abuse the Law to its own benefit. The only true way to fight evil is to ignore the Law and terminate it by whatever means necessary. Once identified, evil can thus be swiftly destroyed without relying on the courts and legalities that evil flaunts so effectively.
