HDMI cables

[Filterlab]

Mmmm, not sure though.

I have a techlink HDMI cable which is a beast of a thing, and the results are superb.

However, I spent £400 on speaker cable so I may be slightly biased towards quality cables.

Good cables will yield more noticable results with analogue sources and less so with digital (as Greenmatiz said), although with digital it will still make a difference as digital signals are still delicate and will be susceptible to outside interference.