I still gotta say that the director did a good job of showing Light being THE premier egotistical bastard bad guy who killed people so he could become God. Not so he could help the world which means by the end of the series he pretty much needed to die since he became such a douchebag.
Still I would have rather the series have taken a turn with L's death with Light outright winning control over the world now that his nemesis is gone. And then the author showing the sociological implications of that versus what they actually did. Which was get a lesser L who no one liked and then have Kira die stupidly at the end.