"1080p24" (ATSC) is the professional HD movie industry standard for high definition movie playback, which is also used in digital projection in theaters.

Because in movies, 35mm film runs at 24 frames per second (FPS), it's the comfortable standard that the human eye can comprehend.  So if you are running an HDMI connection from your compatible Nvidia Geforce card to your HDTV, in the Nvidia Control Panel you can set your output to run at 1080p24, for a smoother digital format that movies are meant to be seen in. 

This optimal output is mostly geared towards HD DVD/Blu-Ray playback, however standard definition movies will benefit from this as well.

For the best results, and to prevent a jittery picture, the output source should be a DVI or HDMI connection running at 60Hz or more, and the television must be able to support the 1080p24 format.