Harmy's right that the (theatrical) HD DVD looks the best, but there's not much in it really. Basically, all of the old BDs and HD DVDs look very similar. Anything's better than the Skynet release.
You_Too said:
Ok, if a Terminator 2 remaster is on the way, this is what I bet it will look like, old vs new:
I imagine it would look almost exactly like that.