If your HD TV has a HDMI input you can get a cable that goes from DVI to HDMI. Unfortunately a DVI to HDMI cable won't be able to carry audio out from your computer to the TV, but there is a solution for that below.
Connect the DVI end of the cable to your computer and the HDMI end to your TV. DVI to HDMI cables come in various lengths. Select a cable that is long enough to comfortably reach from your computer to your TV.