Batman: Arkham City - Challenge Map Pack
You NEED to have this.
If you think you've gone as far as you can w/ the Arkham City challenges, then you are WRONG. For what you pay, this bundle is an EXCELLENT deal, from the "bank" endurance challenge that The Joker has to The Penguins "endless enemies" challenge to the BATCAVE predator challenge, this is, hands down, THE BEST BUNDLE yet. I HIGHLY recommend this to any Arkham City fan!