You would need a splitter in that case: http://www.newegg.com/Product/Produc...82E16882200023
. The best thing though would be to have a video card that has either 3 HDMI ports or 2 HDMI and a DVI port so you can use a DVI to HDMI port in one of the cases. I'm assuming that you would want the three displays to be used for extending your computer's desktop for more space, if so, then you would need three ports on your video card.
However, if you're just looking to duplicate the display of one monitor to the TV, then the splitter would probably be your best bet.