Hard, aggressive music

[beaky]

You'd be amazed at how fast and how heavy some of the rock was that spawned so many of the bands mentioned above...
Sabbath may be old, but without them, there'd be no metal. There was nothing like it before they came out. They rocked, very hard and very fast sometimes.
Some of their stuff is sort of psychedelic-jazzy, but check them out. Every album  up to Never Say Die has phenomenalsongs on it.
Also, Deep Purple were incredible. Forget Smoke on the Water; listen to the album In Rock some time...

Then there's Rush... Cygnus X-1, La Villa Strangiato, YYZ (which is based on the rhythm of the Toronto VOR Morse ID)... all heavy, frantic tunes. Rush came up with some of the best metal riffs ever.

Motorhead is another old band that will fracture your skull...

Or howzabout some early great punk rock, like Black Flag?
Or the true fathers of punk rock, The Stooges? Fun House is 45 minutes of howling rock insanity...

[killerbunny]

If you like something different, try the Mars Volta

Not quite like the offspring though

[AlphaBravo]

How about: Iron Maiden - The Wicker Man
                                      - Hallowed by thy name

etc...