What you need is a graphics card that can output to TV as well. I think most of the nVidia series graphics cards offer such functionality.
However, if you own a Digital LCD TV then chances are that it has a computer input. In that case you just need to connect it with your computer using your moniter cable.
Hey everyone. I've been looking to ask this for awhile now. How would I go about hooking up my Desktop PC to my TV? Is there some sort of adapter that connects the normal monitor slot on the back of my PC into a normal Red, White, and Yellow input on most TVs? Any help on this would be greatly appreciated.