That's the one! I was never really interested in multiverse games before, but man, T9 is amazing. You want some writing to knock your socks off? Read this thread (http://community.livejournal.com/trans_9/22865.html?thread=2047057#t2047057). It's pretty long, but seriously, read all of it. It's that awesome.

(Helps if you know DC Animated canon, but even without that, it's still epic.)