Here is a long thread that's a good read. It covers a lot of information from really good and very inexpensive DIY stuff to some really high end stuff.
http://www.audiocircle.com/index.php?topic=3640&postdays=0&postorder=asc&start=0I just did a digital cable comparison recently and liked the one from Bolder Cable Company the best, so I guess you could say I am a little high on his stuff right now.
His stuff may just outperform a lot of the really high dollar stuff while being pretty affordable at the same time. Be sure to look at it. He has a forum here.
I'll try to get a review up soon on the digital cable.