Instead of posting about the feature-length films of these comic adaptations, today you'll be getting my thoughts on the animated versions. But the double-feature is not just because of their shorter lengths, but because they share some similarities that make for an interesting side-by-side comparison.
The two are perhaps the best known superheroes of 20th century fiction. Though the production of the two series is separated by 50 years, they both have a similar aesthetic: beautifully animated and visually engaging pieces, with the impact of Art Deco evident in their styles. Although Batman: The Animated Series is significantly darker, its creators have cited Superman's influence in its design.
Perhaps more interesting than the visual aesthetics are some of the latent issues and their subtle, or not-so-subtle, incorporation into the cartoons. One such example is the presentation of the villains - in both of these cartoons all the villains are crazy. I mean, totally off their rockers. Pretty much all of them have some sort of mental instability, as evidenced by all the villains in the Batman series getting sent to Arkham Asylum rather than jail/prison. I think it presents an all-too-prevalent and incorrect view on criminality, i.e. that sane people don't break the law.
In addition to what that says about criminals, on the flip side I think it's an incredibly unhealthy attitude towards mental illness. Sometimes criminality and mental illness overlap, but the majority of the people who fall into one of these categories do not fall into both. One could argue that if you're unfortunate enough to get sent to prison, it's entirely probable that you'll leave with much less mentally stability than you had going in, but that's an entirely separate subject.
We'll wrap up this critique with the not-so-unbelievable racism present (mostly in Superman). Aside from the fact that there are zero non-white heroes in these cartoons (or in most mainstream media in general), the Superman episode The Mummy Strikes is pretty blatant in its demonization of Africans. Spoiler: it's about Superman vs. mummies come back from the dead.
Racism aside, this might be my favorite episode of the set - because these mummies are hands-down the best looking back-from-the-dead men ever depicted in film (to my knowledge). The pharaonic guards come back exactly as they were in life, with none of that gross decayed bandaged business. And let me say that these are some fine looking animated men. Yeah racist 40's America, way to make it obvious that handsome African men with finely sculpted bodies pose much more of a threat to you than the undead.
For more 40's racist portrayals of people who don't have white skin, check out Jungle Drums for the stereotype of uncivilized natives. But don't just take my word on it, thanks to the public domain you can watch the Superman episodes on the internets! The three episodes in the tape referred to in this post are Jungle Drums, The Mummy Strikes, and Secret Agent.