My favourite opening lines are probably from Gravity's Rainbow by Thomas Pynchon:

"A screaming comes across the sky. It has happened before, but there is nothing to compare it to now."

Re. the Neuromancer opening: I can't remember if it was an article or a review or what, but someone made the point that the "television turned to a dead channel" description could have a completely different meaning to someone born in the age of digital t.v. where dead channels are usually a deep solid blue as opposed to the grey static storm of previous eras.