Since I already see Batman TAS and the Simpsons on here, here's an underrated one. Exo-Squad. Obviously this is a show designed to sell toys, but it dealt with topics like: the horrors and pointlessness of war, death, the ethics of genetic engineering, what it means to be human, slavery, and a bunch of other topics…

Still the best theory for the ending of the series I've come across yet. Make sure you read some of the comments, they really help to connect some of the dots and expand on it. I feel this is much more GRRM'esque than anything else put forward: