Something harder than Muse but easier than Iron Maiden. Something around the difficulty of Cliff-era Metallica besides Cliff-era Metallica.
you could look into Caught in a Mosh by Anthrax. Not really that hard, it's just fast.
So that with good courage we say, “The Lord is my helper. I will not fear. What can man do to me?”

-Hebrews 13:6
Take something beyond your ability and slow it down to half speed. Slowly speed up as you're comfortable.
Do you feel warm within your cage?

And have you figured out yet -

Life goes by?
Quote by Hydra150
There's a dick on Earth, too
It's you
Some Coheed is around there. Mostly stuff from SSTB and IKSSE: 3. And IMO, aside from Hysteria, Muse stuff seems pretty easy.