Is NLE CHOPPA the smartest rapper? After hearing his lyrics, i'm gonna guess probably not.

OK, are you looking for essential listening, or my favourites? How about essentials, stuff that maybe you don't listen to every day, but everybody should at least hear a few times for reference. Music that can come in handy at the cocktail party, so you can get an idea about what people are talking about.

1 Shpongle - the greatest psychedelic group of all time. (or: Mystery of the Yeti, Taruna)
2 Lee "Scratch" Perry - the original dub master (or: King Tubby)
3 DJ Philippe - The original and one of the greatest Acid House producers (or: Frankie Knuckles)
4 Ozric Tentacles - What has happened to psychedelic rock since pink floyd
5 Jesse Dangerously - my friend, and the smartest rapper around
6 Merzbow - When somebody says they've heard the loudest music in the world and they aren't talking about merzbow, they need to STFU
7 Discordance Axis - When somebody says they've heard the fastest metal in the world and they aren't talking about Discordance Axis, they need to STFU
8 Robert Rich - One of the greatest ambient artists around, beautiful, melancholy, ethereal stuff (or: Alio Die, Steve Roach)
9 Kraftwerk - What can i say, the fathers of electro, techno, industrial... the ones that started everything...
10 Congo Natty - The original junglist. "Amen Brother" broken and chopped to bits, with ridiculous ragga toasting, and bass (or: Roni Size, Dillinja, Dead Dread)

Yeah, certainly not a complete list, but a good start. At least be familiar with those and you'll be in good shape.

To be sure, I only really listen to Shpongle and Robert Rich on that list on a regular basis, but to me they all represent the most creative and groundbreaking artists I can think of on the top of my head.