Is it worth buying a top of the range HDMI cable?
The Longer Answer
No! No! No!
OK, we won't do any in-depth scientific comparisons as it really isn't worth it. HDMI is a DIGITAL format - that is it either works or it doesn't. If the cable is in good order you'll get as good a picture as you would with some uber-heavy, gold plated, oxygen free alternative that costs ten times the price. We would NEVER spend more than a crisp tenner on an HDMI lead - and that really is at the top end of the budget.
Cheap leads work just as well as any other, but you might find that the cheapest have poor build quality and fail. Buy something over £5 though and chances are it'll outlast the lifetime of your TV. Never spend anything more - there is no benefit and anyone selling them under the guise that it will improve your viewing experience is either misinformed, lying or (in our view) attempting to defraud you.