Best Deal for 20% off GS Birthday Coupon?

I have to use this coupon soon.
20% off a pre-owned game.

I was trying to see if there were any good games to use this on for the Xbox 360.

I'm down to Hitman: Absolution and Batman: AC GOTY.
What should I choose? Or is there a better option?

Thanks in advance!

I've never played Hitman but Batman is an A-mazing game, there is so much to do it really takes a while to get old.