I bought a new Plasma TV, now what?

I am getting a new surround sound this weekend. I just want to hear it in person before I buy it. I already saw the TV in person, but the price was better online and Sears doesn't match the online price of THEIR OWN WEBSITE!

I have an HD DVR, I know it has HDMI. Honestly the Wii never occurred to me to hook up via HDMI, the graphics are pretty lame on it, I doubt HDMI will improve it at all.