Batman and it ain't even a contest. inFamous felt like a sandbox game starring a generic guy with super powers. Batman was the perfect (and I don't use that word lightly. I only use the word perfect to describe things that are perfect, mildly competent, and everything in between.) video game version of decades of comic book lore. The narrative was tight, the graphics were impressive, and the package was better than anybody had any reason to expect. I finished it multiple times whereas inFamous prompted me to quit after another "kill all the guys in the area" mission.
I've heard that inFamous got better and more gripping but I spent the whole game (I feel like I got halfway through it) waiting for something awesome to happen. (I bought both of them the week that they came out, btw.) I look forwsrd to inFamous 2 more than any PS3 game coming out this year (except Uncharted 3) but the first game didn't do it for me at all. I believe Sucker Punch will bring the goods this time.