It's the one listed as HDTV cable... I don't think mine supports HDTV, I think it's just a buzz-word they're using to make it seem cool.
I have to plug that in, and then there's an S-video on it that I would use, were I to use S-video. I didn't have an S-video connector on my TV so I used one of the YCAs and just plugged it into an RCA input jack (yeah, I know, cheap-arse way of doing it, but it worked!)
EDIT: If you want I can pull up the manual/paperwork that came with my video card and see if there's a technical name for that part, or whatever else it says about TV-out. That will have to wait til this evening, though.