Given that LCD panels can't pull off much more than 1500:1 natively, and every panel made today does that. Anything more is from tricks with the backlight, and basically lies because you can't get near that with a uniform backlight with real content only test patterns.
So making the backlight able to dim down to just about nothing when measuring the black, and making it twice as bright as model which measures 30,000:1 will get you up to 70,000:1. But since real world pictures have bright areas on the screen most of the time the backlight will usually be run up almost all the way, washing out the blacks.
Again look around to see if there's a control for backlight levels, and cut it down. This may also be labeled as a power saver mode. Some sets also adjust the backlight to follow the Brightness or Contrast controls.
That said, I don't like Samsung sets. They may be the best of the cheap stuff, but they're still in the cheap pile. Panasonic or Sharp are the way to go for LCD (not that I'd buy an LCD anyway).
