HDMI is the way to go, the Sony cables they usually recommend with the machine itself are fine, they cost about half the regular ones so I bought two myself (one for the slim and one for our HD decoder).
Edit; they cost less than half when I checked now. I bought my cables (3 meters) for 350 NOK each and the cheapest alternative here was a Supra HDMI 1 meter cable for the same price...







