Pros:

• Neat, gritty, realistic environment is perfect for Batman
• Tons of little extras
• Awesome characters--even the minor characters are great
• Mark Hamill Joker
• Perfect voice acting for almost all characters (again: Mark Hamill Joker)
• Great story

Cons:

• Story feels short
• Kevin Conroy's voice not as good as in the animated series for some reason
• Some classic Batman villains show up but aren't actually fought
• Boss fights are easy and repetitive

Overall, 9.0. Awesome game; can't wait until Arkham City comes out.