Let's face it: it is an odd story. Especially in a Christian context. God is good and what he does and decides is always right, right? On the other hand: he created man, didn't like what he created, destroyed it all and then created it again. That. Doesn't make sense.
And I'm not even going in to the whole genocide and incest part of the story.
In any case, Darren Aronofsky - whose films I tend to enjoy a great deal - recently made a film of this bizarre story, following upon which Nick Cohen wrote a hilarious review.
I point to one paragraph in particular:
The Ten Commandments do not condemn slavery or child abuse. Instead of recommending a moral life, four of the commandments are merely the instructions of a jealous, not to say vain God, on the importance of revering Him and Him alone, honouring his day and respecting his name. How could a Hollywood liberal tell the Noah story without casting God as the villain? He is a dictator who demands total obedience.
This both misses and explains the point.
The ten commandments were a contract. A political agreement, a land rental deal, a right for this group of citizens to settle in this master's land. This is precisely what makes the ten commandments so remarkable. These types of deals were struck all the time between tribes and local powers (kings, etc.). The right to reside on the land came with a commitment to, perhaps, fight in their wars, or contribute their food. The ten commandments are the first record we have of this same type of deal - common and normal in its historical context - being struck with a deity.
Now read the paragraph again.