It's not often a game overwhelms me with content, yet this is exactly what Arkham City does. During my time in the horrifying prison I solved some murder cases, helped out some political prisoners, hunted down the Riddler and his challenges, and got watched by a mysterious figure. 
Batman: Arkham City is simply over flowing with awesome stuff to do, and that's without even mentioning the amazing story. The pacing of the game is darn near perfect. One minute you could be brawling in the street, next silently picking off foes, then racing across the city to save a hostage.  
If you've played Arkham Asylum, you know how good the combat was. Now with an expanded move set, multiple counters at once, and seamless gadget usage, it may just be the greatest thing ever. For new comers the best way I can describe it is comparing it to a musical instrument. You can button mash and have a little fun just like you can mess around with random notes. However, take the time to learn the moves and style and soon you're making beautiful music. except instead of hitting notes, you're hitting faces, but same difference right? 
 (He's either deep in thought, or getting ready to swoop down and beat the living snot outta somebody. You decide)

As great as everything is in this game (and it's wonderful) the thing it does best is make you feel like Batman. Whether you're swooping down onto an enemy, analyzing a bullet hole to see where the shot came from, or just kicking butt, you feel like Batman. 
If you are a completist like me, be ready to sink countless hours into this and love every second. If you're not, be ready to enjoy one of video game's best adventures. To put it simply, I've played a lot of games, and I can count on one hand how many I think deserve a 10. Arkham City is now one of them. This is the Batman game we've all been waiting for. 
 (This guy's got plenty of stuff for you to do. Also, he's a smart mouth jerk)


A Special Note On Catwoman 
Buying the game new (or used at GameStop) will give you a code to download Catwoman as a playable character. Her section is about %10 of the game, but very worth it. The game switches between the two characters cliffhanger style. Not having her sections can definitely hurt the story's pacing.