I actually like Black Sabbath, Slayer AND Pink Floyd, but maybe that's just me.

Anyway, Floyd are great. Check out their album "Animals"-- many have argued that is where the distinctive "Pink Floyd" sound emerged, to be refined on such monoliths as Dark Side of the Moon and The Wall.

Other faves:

Nile Song
Set the Controls for the Heart of the Sun

and, of course, who could forget:

Several Species of Small Furry Animals Gathered Together in a Cave and Grooving with a Pict

Smoke a fattie and enjoy, I say.