Rather than try to apply game alignments to real world situations, I'm going to try to argue that the current game alignments are useful as a predictive description of a creature.
If a creature is:
Good, you can trust it to be basically nice, but you can't always depend on it being honest or honorable.
Lawful Good, you can expect the creature to be basically nice, AND you can usually depend on it being honest and honorable.
Unaligned , you can generally expect the creature to be "okay" (i.e., not a total douche), but you can't expect it to be honest or honorable unless there is some OTHER reason (strong law enforcement, scared of you, took a serious oath). You can usually negotiate with it (unless it has you fooled) and you can probably expect it to be trustworthy if you force it to surrender.
Evil, you can't even expect this creature to behave like anything but a total douche, but, based on the actual creature and the situation, you might at least be able to trust it. If the reason is good, it will probably keep a promise. You might be able to negotiate with it, or get it to keep terms if it surrenders, so long as you don't expect too much.
Chaotic Evil, you can totally expect this creature to be a complete douche. You can't trust it as far as you can spit it. Beat it half to death, force it to surrender, and turn your back? It will go for you. Never forgive, never forget.
I feel that those are basically useful roleplaying/gaming distinctions.
We can make friends with the Good guys, even if we have got nothing to offer, though unless they are Lawful Good, they might be putting us on a bit. Even if they are getting whipped, they will probably still help us.
We can make friends with the Unaligned guys, though we have to sweeten the pot. They will probably run if they are getting their butts whipped.
We can't really make friends with the evil guys, but if they are screwed, or if the deal is good for both of us, we can at least work with them. Keep an eye on them, though.
The chaotic evil guys give us the choice of fighting them now, or fighting them after they betray us. These guys are never going to be trusted.
I think people are trying to make alignments do too much, and carry too much philosophical baggage. Instead, I really think they are just supposed to be (and are quite useful, to me, as) a quick indicator of 'in game' decision-making.