Would need to know what it says the resolution is.
If it was an old movie, just "bumped up" to HD specs, then there's not going to be a lot of improvement.
As far as the cable goes, I use cables I buy from [ame="http://www.
amazon.com/Super-Resolution-Cable-DVI-Gear/dp/B0002L5R78/ref=pd_bbs_sr_1?ie=UTF8&s=electronics&qid=1204150160&sr=8-1"]
Amazon for no more than $2.43 each[/ame].
I purchased these per
CNET's recommendation (There's no reason to pay extra for HDMI cables.) and my HD channels/Blu-rays look great. There's no big difference in cables. The signal is digital, either you have it or you don't. A $50+ cable isn't going to help.
I like going to stores like Best Buy and listening to the salespeople push the expensive cables on ordinary people. Followed a salesman and customer around a Target last weekend listening to the load of rubbish the salesman was unloading to sell the high-end cable for an HDTV to a guy. Wanted to but in, but I'm too nice.