I picked New 52, it has the best superman outfit, and intro. New 52 batman is my favorite batman costume on here, i dont really know why i like it so much. Wonder Womans outfit is okay, i think her face looks better in her new 52 outfit for whatever reason, though i might just be imagining it.
second would be bad girls, because all of the skins look great, and selina kyle gives me hope for a helmetless hawkgirl, and better looking faces.
I kinda regret not getting Red Son instead of Arkham, but I'll probably buy Bad girls pack, dat WW.
You're not missing much. The missions are crap unless you wanna use the easier ones to skip over some main missions (did this to get New 52 Shazam a bit quicker), and the costumes are kinda meh except Red Son Grundy. Arkham pack makes all 3 look great though, especially Catwoman and Batman who really needed it.
Btw how'd you like playing through Arkham City as Catwoman?