Let's get this straight out of the window: the main character is a bad guy. "I'm the bad guy?". Yes you are.
That said, Michael Douglas' performance is great, he nails is as the psycho he portrays, but also breaks down very genuinely in the scene where he is "accidentally" holing that girl hostage. Also liked the scene where he kills the nazi. Opening scene was also a perfect way to set up the rest of the movie. The end felt really cliché though.
Overall an enjoyable movie, with beautiful shots of L.A., where one guy just loses it.