Sorry it's late but I have a Samsung HD TV & use an DVI > HDMI cable & it looks great.
The probelm you're having (I think) is you're not using the dedicated PC HDMI input.
PC's have a slightly different colour palet which needs taking into account on a TV.
Otherwise the images look pale & washed out.
Check your TV manual, on mine the HDMI input 2 is the PC dedicated one but yours might be different.