Stephen Hawking's Final Destination

Alright, listen up buttercup. The joke is playin' on the fact that Stephen Hawking was a brilliant scientist who used a computer to communicate because he couldn't speak. So, the punchline suggests that after he kicks the bucket, you gotta decide whether he needs a traditional funeral or if you should just haul him over to PC World, which is like a Best Buy but British, implying he's more machine than man, you dummy.