I'd go with Alien, here is why:
-Alien theme is most interesting to me
-Alien seems to have the best layout
-I also suspect Alien will have some intricate code with what I read... Supposedly they are aiming to have balanced scoring, opportunities for stacking, different weapon benefits (I'm sensing a Dr. Who alteration to gameplay), balance of modes and non mode goals.
-Very cool Xenomorph toy, jumping face grabber slings, and alien eggs that glow.
-Multiple wizard modes
-Batman seems too similar to the Dark Knight, I don't care for the old TV show, now if it was Batman the comic or Animated Series, that may increase my interest.