Erm...Harley Drive, most people HAVE heard of him, or at least know what The Scream looks like, as it's one of the most referenced and parodied works of art ever.
That being said, I don't think his paintings particularly effect today's society.
Normally I get irritated when people blatantly try to get people to do their homework for them on here. But if this is an essay topic or something, I actually sympathize with you because it's a terrible one. Please ask your teacher to think harder about assignments and give more thoughtful essay prompts, because this is just awful.