Question : Problem: Which would provide the best picture quality for HDTV hooked up to my computer

I build a computer out of left over parts from upgrades and am hooking it to my HD TV.  It has a Zogis GeForce 8600GT video card which has a DVI and S-Video out.  Currently I am using the S-video to hook my computer to my tv but was wondering if it is worth getting a DVI to RCA Component (RGB) adapter and hooking it up that way.  Would I gain any video quality.  My goal is to completely do away with my cable box and just use my computer as my DVR.  Also using a Hauppauge WinTV-HVR-1600 TV tuner with both cable and HD antenna, but I think that is irrelivant to my question.

Answer : Problem: Which would provide the best picture quality for HDTV hooked up to my computer

For best results, connect using the DVI port to the HDTV, if it has a DVI input.  If it doesn't, but has an HDMI input, get a DVI-to-HDMI adapter, or DVI-to-VGA if the HDTV has VGA input.  Only if you don't have any of these ports would I choose a DVI-to-Component adapter, since all of them are higher quality than component.  Component is better than s-video, so you would still see an improvement, but investigate the other connections.  In general, stay with digital connections if you can; otherwise, choose the transport that has the most separation of signals (RGBHV, or VGA, has 5 signals; component has 3; s-video has 2; and composite has 1).