Allegedly any cheap HDMI cable should do as it's a digital signal. If you want to fork out £80+ go ahead, but I'm using a cheaper £15 (I think) one from Argos.
I would like to try an expensive one to see if there is an improvemnet or not tho.


PS Just remembered, more expensive cables are meant to be better over longer distances, I think it was something like 5 or 10m, but can't remember.