Maybe a bit mainstream, but here's my suggestions for today (they might change tomorrow).
Bat out of Hell - Meatloaf (can't have bike anthems without it)
The Prisoner - Iron Maiden (a good thrash and great lyrics)
Red Barchetta - Rush (OK - it's a car, but it's still a good track)
Paranoid - Black Sabbath (Classic rock)
She Hates Me - Puddle of Mudd (Just sing along inside your helmet)
Seven Seas of Rhye - Queen (Dated but good)
Kashmir - Led Zepplin (Specially for enduro riders)
Song Number 2 - Blur (Woo hoo.....)
Just don't play Song No.2 anywhere near a speed camera - you'll be waaay over the limit when it finishes
Keith.