The main problem is, all LCDs don't support this feature, and the ones that do supposedly, only support certain file types/sizes/codecs/hard drive or USB drive sizes. That part's a little bit of trial and error, especially depending on which LCD HDTV you actually are working with. What's your proficiency for this kind of thing?

I find a cheap DVD player to be the best option for compatibility if you are somewhat unfamiliar with files types/codecs/etc. Burn your video files to a blank DVD using a reliable free software such as DVD FLick-